What's the wireless chip inside it? (Sorry, I'm being lazy, can't be bothered to look up your code)
I'd suggest Fedora 7, which should be released by the end of the month. I'm sure everyone else however will suggest the new Ubuntu, Feisty Fawn is it? That seems popular with well, everybody.
I've had reasonably good experiences with Fedora Core 5,6 on my T41p, but all your hardware is different. My only major stumble was getting wifi to work, as I have the Thinkpad branded device I needed to use the madwifi drivers which aren't included by default in Fedora.
Have you had any previous Linux experience? I can point you to a very good FAQ for Fedora -
http://www.fedorafaq.org/ . That'll help you with all the basic questions people have, like getting mp3 to work. Stuff like that.
Actually, when thinking about it now. If you want to install right now. Then download a Ubuntu live CD and see what works, that's the beauty of the Live CDs. Else wait till the end of the month and download the new Fedora 7 live cd. Should be good.
EDIT: You're a lucky one, just looked up your code and you've got Intel abg. That'll work out of the box to my knowledge. I don't think you'll have problems with your screen resolution, that was solved for me in Fedora Core 6. I did however have a lot of problems with suspend-to-ram, never got it to work. But we're talking about Fedora Core 6 here, as I say, wait for Fedora 7. Good luck.
EDIT2: Looks like I'm feeding you wrong information, bypass much of what I'm saying and go onto this guide.
http://www.thinkwiki.org/wiki/Installin ... inkPad_T60