Honestly, I would help you if I wasn't at work. But they kind of frown upon me helping people that aren't paying me to do that sort of thing. Off the top of my head you can go to
http://www.qeradiant.com and get the quake III mapping tool. The older versions (Q3Radiant) are what I use however if you don't mind an ugly interface GTKRadiant is supposed to be more powerful (however more memory intensive).
http://www.planetquake.com/bighouse is where I go for all of my texture needs when mapping. Be tasteful, however, when you choose texture sets. It's easiest to go with a single set rather than pull many of your favorite textures from various sets. Remember that every new texture you use you must include with your map, so these can kill you on file size.
As far as tutorials go, I reccomend against anything but the Q3Radiant manual. However most of the time I tell people to talk to me instead of consulting a tutorial. But again, I spend all day at work so I can't do that. Keep an eye out for some guy named "Ricebug." People seem to like his tutorials a lot. He runs a webpage with tutorials but I've no clue as to where you might find it.
