Windows XP tech questions

[Flock of Moosen]

Hopefully someone out there knows the answer or at least knows what direction to point me in for answers.

I'm new to the whole Windows XP world after living in 98ville for about 4 years. I just got a new system and one of the first things I did was run MSCONFIG to see what programs were loaded and running. I expected to see a few, but not as many as there were. There are a bunch, under both the Services and Startup tabs and I have no clue what most of them are. I don't want to uncheck them without knowing what they are, what they do, and why they are even loaded in the first place. Do any of you know which should definitely remain loaded or at least know of any sites that can help me out?

Another question of lesser importance is about WINIPCFG. I tried running that just to see if it was the same as the one with Windows 98 and it's not even on my system. Is it under a different name now or am I missing the program for some reason?

Thanks in advance for any and all help.