7.10 is probably better, I assume you haven't ever used Linux before? Probably has better support for more recent hardware, and you'll probably find yourself breaking it, formatting and installing something else before actually NEEDING the long term support feature, it is more of a feature for security critical or business systems where reinstalls or dist-upgrade isn't ideal. I think 8.04 is going to be a LTS release too if you want to hold out for that and think that you'll be using it long term. Basically, I think you want the most recent you can get for hardware support reasons. Some people here are quick to bash Ubuntu, but it is perfectly fine for learning on, just ignore them. Just know that there are more "power user" distributions out there, and use Ubuntu to ease yourself into some of the more low-level stuff. Learn what hardware you have, find out what modules you need to load to get them working, read install guides (Arch and Gentoo wiki's are good for this) and then maybe try something more advanced once you feel comfortable with the terminal and main commands like ls, cp, mv, chmod etc. sudo is actually good for a new user, as it stops you accidentally doing stupid things as root. If you really want to stay root, all you need to do is "sudo su", and voila, you have a root terminal until you type "exit". Just like a normal user terminal on any other distro. Good luck mate.
I'm fairly new to Linux. I started with 7.04. As soon as 7.10 GG came out, I wiped the partition and installed it. It is absolutely awesome. It takes a lot of patience and the willingness to think non-windows. Learning it kind of reminds me of taking trig back in high school. I didn't have a clue for a couple of weeks and then all of a sudden......it clicked. I have also downloaded and installed Opensuse 10.3. Another great distro.
Mick.. I don't randomly bash ubuntu. I disagree (along with a large percentage of the linux community) with the sudo system.. It reinforces all the windows stupidity of an "always administrator" arrangement. Sooner or later some scumbags will get wise to the fact that it is very easy to exploit and will lead to a huge rootkit and virus explosion. The last ubuntu distro I looked at still had the password file globally readable after install.. Right on the kind of system which needs to be secure. the new users system. I believe you should ALWAYS have a real root account, and to be forced to use it to make any critical system changes. sudo brings all the windows insecurity into the unix world, and is a bad thing. http://lwn.net/Alerts/Ubuntu/