This book by John Marsden is the best book I know of for hopeful writers. It contains advice from Marsden, who used to be a teacher and is now a rich writer, as well as writing ideas and springboards.
The best feature of the book is the "Yes you can do this!" attitude Marsden adopts. Many writers who have made it like to tell you how difficult, depressing and draining writing is, justifying their own egos and deflating yours. Marsden prefers to assume that if you are reading this book, you must be interested in writing, and with some hard work you can at least be a better writer than you are now.
The back section of the book contains long lists of writing projects, categorised by length, style or purpose.