Okay, I'll stick my neck out and let others chop it off. Here's my guess for what you want:

1. Get as big as you can afford but not less than160Gb. You can get 320Gb or more now, and HD space is so cheap you should consider getting as much as you can.

2. 2Gb Ram, assuming you're not intending to go for a 64-bit machine (may be too expensive?) is the maximum usable under 32-bit win xp. Go for as much as you can afford. With a modern board it's likely to be DDR memory, which is the successor to SDRAM.

3. Buy nVidia. I'd hesitate to suggest a model - these things keep changing - but all the recent ones seem to work well enough with OpenGL. So do ATI cards allegedly, but I've had some bad experiences with them.

4. Agree entirely, go Intel! Probably a P4 will do, 3GHz plus, but I'm not up to date with the latest Intel processors; I just know that they get very expensive as you get to the bleeding edge!

5. I always use Asus mobos when building machines, I've never had a bad experience with one. So I don't know much about other makes, I'm afraid.

6. Yes, definitely a DVD burner, not much more expensive than a CD burner now. You can even find good inexpensive dual-layer DVD burners, although the blanks are expensive.

7. Fair enough.

8. Sound is probably on the mobo nowadays, which is good enough for listening to video tuts, etc. Networking also probably on the board. Make sure you have plenty of USB ports, preferably on the front of the machine, so you don't have to grovel round the back to plug things like memory sticks or camera cables in.

9. Go for 400 watt minimum. You can run into problems with lower rated supplies.

You can either source this stuff and get someone to build it, or buy a ready-to-wear PC. In that case you get what you're given, but the above might give some pointers to what to look for.

Steve