Lettering usually comes last in the comic book production process, though this is not always the case. Whatever stage you're at I can advise a suitable approach to helping you see your comic to completion.
After an initial discussion, we can reach an understanding of your project's goals, the style of your comic, the type of lettering you require for your project and a deadline date.
If you're happy to move forward then you would supply me with the pages you need lettering. I would letter a few pages to make sure we're on the same wave length. If the work I've produced works for you I would letter the rest of the comic, supplying you with completed batches for your approval.