Yes, you need to know if it works with your OS, though most will work with XP. Check if it works on the Windows XP HCL listing found here.
Whatever you buy, check it from there.
As for a joystick, I have the Logitech Attack 3
and it rocks. I've heard of it failing though...like some of the buttons would stop working. For one day, my throttle control failed, but it came back later 0_0. I still LOVE it, it looks like the traditional joystick and still looks cool with 10+ buttons. It rocks. It used to be $33 when I bought it, so its crazy that its freakin $16 now...crazy. One thing that the Attack 3 lacks though..you can't control the plane on the X-axis (aka. The Rudder). You can roll it and lift it, but you can't slide it. You'd have to use the "A" and "D" keys to do that.
If you're looking for something a bit more advanced or something...theres the Logitech Extreme 3D Pro.
Its a bit flashier than the Attack 3, but I haven't used it myself so I can't comment. The price also went down for this. I believe that this joystick CAN slide and turn across the X-axis.
Looks good, but if you look at the pics, theres something next to the handle on the joystick that personally would bug me. I haven't used it, so I don't know what it is...but its there...ugh...