Great advice on editing your novel (more or less) from people who know what they're talking about:
I try to leave out the parts that people skip. ~Elmore Leonard
To get the right word in the right place is a rare achievement. To condense the diffused light of a page of thought into the luminous flash of a single sentence, is worthy to rank as a prize composition just by itself...Anybody can have ideas--the difficulty is to express them without squandering a quire of paper on an idea that ought to be reduced to one glittering paragraph. ~Mark Twain
The personages in a tale, both dead and alive, shall exhibit a sufficient excuse for being there. ~Mark Twain
An author should
... Say what he is proposing to say, not merely come near it
... Use the right word, not its second cousin.
Don’t tell me the moon is shining; show me the glint of light on broken glass. ~Anton Chekhov
Substitute “d***” every time you’re inclined to write “very;” your editor will delete it and the writing will be just as it should be. ~Mark Twain
Quantity produces quality. If you only write a few things, you’re doomed. ~Ray Bradbury
You have to know how to accept rejection and reject acceptance. ~Ray Bradbury
Vigorous writing is concise. ~William Strunk Jr.
Parts 1 and 2 on Revising and Editing have more practical resources, if you're interested.