Some of the names of my characters are old Celtic names, but they are pronounced differently from how they look. For example: Heulyn is pronounced Hil-een. Do I tell the reader how to pronounce it there and then (by use of an asterix?) or do I put a little guide in the back of the book, or do I write the name as how it's pronounced?
Is it important for the story or for you that the reader "pronounces" them correctly in his/her mind? The novel I'm working on with my hubbie contains several characters that have non-English names, and we explain their pronunciation only when it serves some other purpose than educating the reader (there's one gag about this guy explaining this chick why it's important that she doesn't mispronounce his name while he's mispronouncing her name in the process).
it's never a good idea to give characters names that the average reader will have trouble pronouncing... period!
I don't think it would work for all characters, but if there was one whose name you really want pronounce correctly, maybe you could coax the reader by having a song, laudation, or poem written about that character (see Tolkien) and use more common words that rhyme with their name.
If this is your story that takes place in the future, you could always tweak the spelling of the names to make them easier to pronounce. Some names do change over time, and it's not uncommon for a name to have several different possible spellings (I've known a Kaleigh, a Kayley, and a Kailey, all pronounced the same way). But unless it's important to the story, it shouldn't really matter how your readers pronounce the characters' names in their heads. I didn't know how to read the name "Hermione" until the first Harry Potter film came out, and by then I was on the third book, but it didn't change the way I interpreted the character.
If it's not necessarily for the story, you don't need to do it. If you want to you can always have an unacquainted character stumble the first time they hear it, prompting the character to give its correct pronounciation. Also, for your information, Huelyn isn't an 'old Celtic name.' It's a modern Welsh name. And it's actually pronounced hay-lin.
But what's an average reader? If the novel becomes huge, it will be read by other than English speakers too. I agree it might not be the most stellar idea to name your characters Ghfrytthää, but since I have no idea what's the average reader - can s/he pronounce Hermione or not - I'd just use names I get a good feel of and that seem fitting. As a kid I pronounced Hermione Her'-Meeh-Oh-Nae. Ron Weasley is Ron Waes-lay. Har'rue Pot'taer And so on. I had no idea how to pronounce the names, but it didn't matter.
If the reader doesn't know how to pronounce it and it really bothers them then they will take the initiative to look it up themselves. Before the (terrible) film adaption came out I worked my way through Eragon and Eldest pronouncing every name wrong - including Eragon!
How do we know that Rowling didn't intend Hermione to be pronounced "Hermi-1"? She is, after all, the first prototype of the Hermi series of magic robots, isn't she? Isn't she?
Because, before the movies came out, she actually answered this question in an interview and blatantly stated the intended pronunciation. At any rate... I've read lots of books where I've pronounced names wrong. I've written books where I've (apparently) pronounced names wrong. I thought that Aron was a girl's name and was pronouncing it weird (I don't even know how to show how I was pronouncing it; it was so off). It wasn't until a friend read over a clip I'd written and pointed out to me that the name was a boy's name and pronounced it "Ah-rawn" that I realized I'd gotten it wrong (and actually did change it because it bothered me that much). If the reader thinks they're pronouncing the name right, then you're good. Your only difficulty will arise if you're giving them a name with such a foreign spelling (such as the one KaTrian used in her post) that the reader doesn't even know where to begin pronouncing the name. Otherwise, they'll tend to revert back to elementary school words for trying to pronounce words. My soon-to-be 8-year-old nephew could probably pronounce "Heulyn." It would come out something like "Hew-leen," but he'd think that was right and he'd go with it. Unless you give readers a reason to think they're pronouncing it wrong, they aren't going to think they're pronouncing it wrong.
http://www.behindthename.com/names/usage/ancient-celtic That's the BehindTheName page for "Ancient Celtic" names if you want to reference it. It usually has a brief history and the meaning of the names that it puts up, if they're available.
They could do that. Or you can put a thing in the back with pronounciations. I've seen it done both ways. I didn't feel it made a big difference one way or the other. Me too! And yes, that movie was a terrible let down. Yes! This is one of my favorite site for names.
Now I'm curious how they're pronounced (haven't seen the film). My Finnish brain pronounces them in my head [ɛldɛst] and [ɛrʌgon] with a rhotic r.
I think it makes sense to have names the reader can pronounce, or at least doesn't get stuck on. I have Welsh friends who use English spelling when they give their names to make life easier: Jerry and Kay instead of Ceri and Cai. About Hermione: I don't think JK Rowling purposely choosing an outlandish name. She is a middle class English woman, and when she was growing up I expect the name was perfectly normal to her--as it was for me. I went to school with a Hermione, and my mother had a friend named Hermione.
You could add footnotes on pronounciation and etymology of the names when each character is first introduced. Such practice has become relatively commonplace, e.g. The Brief Wonderous Life of Oscar Wao.
Generally sites that talk of anything 'Old Celtic' don't know what they're talking about. 'Old Celtic' isn't actually a thing, so by definition anything about it is made-up or misunderstood. If you want Celtic names that are believeable, mean what the website says they do, and pronounced as the website says they are, you're better off searching specifically for Welsh, Irish, Gaelic, Breton, etc. rather than 'Celtic.'
ditto that... i've known how to pronounce 'hermione' [her-my-o-nee] since the age of about 12 [62 years ago!], when i first saw the marvelous hermione gingold's credits on a movie screen... it seemed to me to be the logical pronunciation... turned out i was right, when i first heard it spoken
Garball presented a great trick for facilitating the pronunciation of names or any other words you don't think will be pronounced properly. However, I don't think it's necessary that readers pronounce things correctly. As long as they can easily come up with some sort of repeatable pronunciation, it's all gold. This actually ties into a literary quandary I've tentatively devised an answer for. What is more important? The author's intent or the reader's interpretation? While indexes, guides, and footnotes (like what squishytheduck suggested) get the job done, I've never been a fan of that sort of extra material in books (like with the Pern novels). It's cumbersome having to look in the back or front of the book to find out who someone is or how their name is pronounced. It breaks the flow of the story. I have that same problem with maps, though that's harder for me to reconcile. Hopefully all of this helps. Great information here.
I would say that you put a pronunciation guide in the back of the book. I like reading a book and making up my own pronunciations as to how I think they should sound, and then seeing if I am correct. Maybe I'm just strange, but I really like that style. It seems to give a reader an option as to how they think the names should sound. If the guide is in the front, it seems like it's setting a rule for the rest of the books. A guide in the back seems softer. I don't like being told what to say and kinda "forced" to hear and see it that way.
I think if you're going to add a page dedicated to names and their pronunciations it should be at the beginning of the book. That way the reader doesn't go through the whole book and THEN find out they've been reading it wrong. And if the pronunciation is too difficult or hard to understand I read the book and throw in a different name than the one provided. c; Don't worry too much on people not getting it.