How Not To Write A Novel is one book I really can't praise highly enough. Lots of tips about fiction writing, and then an enormous amount of information about exactly how to go about putting together a query and summary. It's written by two book editors, so they know what makes them sit up and take notice (in the good way or the bad). And it's very, very recent. And funny!
It is an American book, but the standard procedures for US and UK authors are pretty much the same nowadays.
For some encouragement, have a look at
Slushpile Hell. It's a fairly new blog started by a literary agent. Every day or so he posts one of the more... er... interesting queries he gets. They'll make you feel very professional by comparison.
For very serious stuff about writing,
Story by Robert McKee is a book I keep going back to. Strictly it's about screenwriting, but in fact its lessons apply to any kind of fiction. McKee seems to be a bit controversial, with hardcore followers and denouncers, so maybe he's a love-or-hate kind of teacher. The book's a bit pricey, so you might want to borrow it from the library before deciding whether to buy.
Writers' News and
Writing Magazine are sister publications, and both are good. They're UK-based, and frankly much better than the US magazine
Writers' Digest. The
News is subscription-only and is mostly news about publishers, writing competitions, etc.;
Writing can be found at newsagents and has lots of good articles and interviews.