Screenwriting

For now:

Joss Whedon's Top 10 Writing Tips

And voiceovers are for hacks. Unless you're "Dexter" - then it works.

Recommended Books
"Save the Cat!: The Last Book on Screenwriting You'll Ever Need" by Blake Snyder, Michael Wiese Productions

Extremely popular book on screenwriting. Goes more with the theoretical aspect of screenplays. Has sequels.

"Your Screenplay Sucks!: 100 Ways to Make It Great" by William M Akers, Michael Wiese Productions

Also popular, but goes more into technical aspects of writing a screenplay.