Here are some sources I found helpful:
About dot com's intro to Linux
. It's oriented to Ubuntu, but the information is solid.
. It's Slackware-oriented, so it's very good on basics, such as permissions, file structure, and the like.
Garrels's Introduction to Linux
. Extremely detailed and very thorough.
Lenny is a good, solid, stable choice. It's my second choice after Slackware.
Learn it. Then you will be ready to explore other distros.
As for learning how to use a webserver, I would suggest XAMPP
, as long as you aren't planning to open it to the internet.