Just curious, why would you need GCC 3... if you already have 4?

Missing dependencies? Video software like VLC might need libmpeg, libxml and other sound libraries, just to name a few. Check your compile error messages, google it if you're not sure.

Using apt would save you all the trouble, of course.

Usually when you download huge files there's a slim chance of getting bit errors while downloading. It's not noticeable if it's audio or video, but for ISOs it could ruin the whole disk. So people generate a "hash" using a certain maths algorithm ("md5" for example) before it's being served for downloads. When you finished download you generate the hash again yourself and compare what you've got with theirs. If it's different you've got a bad file.

Did you use bittorrent, or http to download the iso? Which version did you get? (PowerPC, i386, 64-bit)

Wireless interfaces might have other names, depending on chipset and drivers used. Atheros chips show up as ath<num>, and some show up as wlan<num>. When you get wireless working type "iwconfig" and the interface that shows your wifi stats will be the right one.

What's your card? Your best bet is to go to the official forums and search if anyone posted guides on how to get it working. In worst cases you just need to kacau around with Windows drivers a bit.