Note that by the time you read this article, things might have changed. Right now Ubuntu 8.04 has just come out, although I'm giving it a week or two so that downloading isn't super slow, and for any immediate bugs to be fixed.
Here's a list of the parts, with some recommendations:
- Processor: Go for dual-core. With triple-cores and quad-cores coming out like crazy now, dual-cores are dirt cheap. Quad-cores aren't twice as fast as dual-cores unless you're doing something that actually multi-threads well like video encoding or serving web pages. For normal web browsing, listening to music, etc. a dual-core is all you'll need. The second core means your system won't die if one program steals all your resources, but adding more cores doesn't really help all that much.
Cache is something good to have. More cache means more speed.
Manufacturer doesn't really matter. I prefer AMD because they generally use less power, they're cheaper, and supporting AMD means that Intel won't get a Microsoft-esque choke-hold on the CPU market.
- RAM: Whatever you want. RAM doesn't care what OS is running behind it. More RAM means things will probably go a bit faster, but it doesn't scale that much after a certain point.
- Video Card: Anything Nvidia. They have much better Linux support than their competitor, ATI. The newer cards will probably not work as well as the older ones, but usually with a little bit of time you can have them running nicely. I wrote an article on how to get it working with a Geforce 8800 GT, I doubt the process is much different for any other Nvidia card.
Don't go with ATI. I tried with an ATI card a couple years ago (Radeon X800) and it was a nightmare.
- Hard Drive: This is an interesting one. Because on Linux you generally split up the partitions more than you would under Windows, you have some more freedom in choice here. The coolest option would be to get a SSD (solid-state drive) for your root partition ( / ) and a regular SATA2 drive for your /home folder. SSDs are still pretty expensive (they're essentially big USB sticks), but they're super fast and don't consume a lot of power. Maybe pick up an 8-16 GB SSD and a SATA2 drive. If you don't want to splurge on a SSD, just get a SATA2 drive (or two).
Brand doesn't really matter too much here, go with whoever you want.
- Case: Get a cool case. Preferably with cool things like blue lights.
- Sound/LAN: Usually your motherboard will have this built in. I usually get an nForce board because of Nvidia's Linux support (you'd think Nvidia is paying me to say all this stuff), but I'd think other companies would have decent Linux support too. If you want something spectacular you can go for a special sound card, but usually the onboard ones nowadays are of good quality.
- Wireless: This is the tricky part. It's harder to find a wireless card that works with Linux. Sometimes different models of the same card will have different chipsets, which mean that they use different drivers. Your best bet is to just look at a bunch of cards and Google for "D-Link DWL-510 linux" or whatever the card's name is. Most of the time you should have an answer for whether it works well or not. Many of them need ndiswrapper, a wrapper for the Windows version of the drivers. It's not too hard to use, although native support is always preferable. EDIT: I use a D-Link DWL-G520. The versions of Ubuntu that I've used on it (Feisty through Hardy) all automatically detect it without any problems. Absolutely no mess whatsoever.
- Peripherals: Any normal keyboard/mouse should do it. If your keyboard/mouse has extra buttons like volume, play, or whatever, it's pretty easy to set them up in Ubuntu. Just go to System->Preferences->Keyboard Shortcuts and you'll get a dialog where you can set the keys. Just click the Shortcut column for the one you want to set and press the key.
Speakers are speakers. If the sound card works, the speakers usually should too.
Monitor: Get an LCD screen. CRT screens are so 5 years ago. Get one between 19 and 25 inches, but beyond that is a bit ridiculous. Jeff Atwood posted about monitor productivity, check this out if you want.
Webcams are a bit touchy. For me, my webcam works but the microphone on it does not. I tackled this a while back unsuccessfully, after I install Hardy I will try it again and post an article about it if I succeed. For now, just get the two separate (microphones are cheap anyway).