You'll most probably need to buy a USB cable seperately.

If your PSP comes with a firmware version of over 2.80, then you won't be able to flash anything, play any homebrew, or anything apart from what your PSP is meant to do. And that's no fun, is it?

You'll want a PSP with a firmware from 1.00 to 2.80. Anything under 2.50 is rare, so keep your eyes peeled. Flashing a firmware has risks that may result in the permanent malfunction of the PSP, but provided you do nothing stupid, you're fine. Thousands of people have done it, with very few casualties.

If you get a 2.80 or under, post again here and we'll help you to downgrade to 1.50. Then, we'll help you to go to 3.03 OE-A (that's the custom one, so no crummy Sony update where you can't do anything decent). Then, upgrade to OE-A' and then OE-B.
That way, you can easily play PSX games, PSP games from the memory stick, homebrew, good-quality movies, and do everything that Sony has included in their latest update, 3.03.

3.03 OE also has a recovery mode, so if you flash anything minor then you can easily restore OE or downgrade to 1.50. If you brick from a firmware update or something, then that's the time you should be worried.
So, if you flash a custom gameboot, icons, menu names, or anything like that, then you're safe, but if you do something like downgrade to 1.50 and pull out the battery half way thorugh, then you're most likely in need of a new PSP.

If you don't get a 2.80 or under, it's essential that you don't upgrade any further, as that may lessen your chances for homebrew or custom firmwares in the future.

__________________