From a short article
by John Naughton on how word-processing changed the way we write:
The most interesting academic study I looked at found that writers using computers "spent more time on a first draft and less on finalising a text, pursued a more fragmentary writing process, tended to revise more extensively at the beginning of the writing process, attended more to lower linguistic levels [letter, word] and formal properties of the text, and did not normally undertake any systematic revision of their work before finishing".
Which strikes me as a pretty accurate description of the problems many people have when they try to write their first novel. Of course, established authors aren't immune from these sins, but in my limited experience of teaching creative writing one of the main reasons first drafts tend founder and stall is that the author spends weeks and months drafting and redrafting the first chapter, trying to get it absolutely right before moving on to the next. My advice is to keep going. Revise the first draft when you have a complete first draft. And when you have assembled the complete skeleton of the story, you will almost certainly find that your precious first chapter contains passages that are no longer relevant. In fact, the entire first chapter might usefully be omitted. (Many authors, confronted with this unpalatable fact, can't quite bring themselves to kill their darling, which is why far too many novels have superfluous scene-setting prologues. In italc.)