1) High Speed Internet
The reason I gave up on Linux five years ago was that I couldn’t get my dial-up modem to work. I have high-speed now, but I tried to set up the modem just to test how difficult it was. After failing with three different distributions of Linux on four different computers I have to recommend that new Linux users make sure they have high-speed. I’ve never had any trouble getting my Ethernet to work.

2) Double whatever RAM the distro claims you need.
I’m putting Linux on my older computers, and I assume most new converts are going to try to do the same. That usually means we’ll be working with slower computers. One of the selling points I came across when I started reading about Linux was that it works fantastically on older computers. However, I’ve found this isn’t entirely true. I tried Ubuntu, Xbuntu, and Damn Small Linux on an old lappy that had the supposed bare minimum RAM, but nothing worked quite right. I eventually just installed Xbuntu and had it boot into text-only mode (and that’s how I discovered the joy of the command line). Recently, I installed Fedora 9 on a 3 year old desktop which meets Fedora’s minimum requirements for RAM, but I’ve discovered it’s safer to stay in CLI, and I’ve ordered more RAM. Whatever the distribution you’re using says you need, go ahead and double it, and you’ll enjoy yourself a lot more.

3) Terminal Skills
The best way to prepare yourself for the trouble you will have is to learn some basic Unix commands. Most of the on-line help discussions use terminal commands, so you must learn your way around a terminal if plan on fixing any of the problems that come up. (These problems happen on M&M too [that's Microsoft and Macintosh] but I’ve found fixing problems is easier when working in a terminal.)

Don’t stress out about this point; learning these commands won’t take much time. I went to the library and got an old book on Unix that had most of the information I needed. I spent about an hour scanning the book and picked up most of the basics and a couple cool tricks. Every new Linux user must do this. Eventually, you will read something that will use these commands and if you have a basic understanding of them, you’ll be able to follow the discussion more easily. Spend an hour learning these commands now, and it will probably save yourself several hours in the future.