You need a screw driver
Optional: A anti static wristband, but you could just touch a metal part of the case at regular intervals.
For components you will need a CPU, a motherboard, RAM (preferable 2 sticks for dual channel) a GPU, a hard drive, a cd rom, a PSU and a case.
is a good place to buy from.
CPU is dependant on what you are going to do, if you are going to game alot AMD 64 if you are going to do alot of video editing/ de -coding en coding than Intel, if you are going to just surf the internet, what ever is cheaper. If you are goign AMD than a DFI motherboard if you are going Intel, than ASUS. Anyone will do for ram if you are not overclocking.
Nvidia for GPU due to Pixel shader model 3 support. The 6600gt will fit nicely into that price range. eVGA or Leadtek for the GPU. XFX are good if you are overclocking.
Antec/Thermaltake/OCZ/Enermax for PSU
Seagate of Western Digital for hdd.
I would stick with CRT with that budget, due to they are cheaper and better picture quality - unless you get a very expensive one. If you get a LCD you will be in danger of getting ded pixels as well.