If he's looking for somthing very simple I would go with the Line 6 TonePort UX2. It's a USB audio interface with different input stages for active and passive instruments, as well as inputs for mics (phantom power included), and line level in. It comes with very simple to use recording software and includes all of the modeling software you will require for a guitar. No external amps or FX processors will be required.
http://line6.com/toneport/index.html?utm_sourc e=Line6Index&utm_medium=Navigation&utm_campaig n=TonePort+image+DropDown
If he is looking to use extrernal modeling (such as an amp, or POD/VAMP/Tonelab) then you will need a soundcard.
Soundcard are much better then USB interfaces in regards of QUALITY and latency. I would recomend anything from the M-Audio Delta Line if using windows XP or MAC OS/X, and anything from E-MU if using windows Vista. Since you have stated that the is just a hobbie it doesn't matter what OS you use, but for more serious use, stay away from Vista (IMO).
M-audio
http://www.m-audio.com
E-MU
http://www.emu.com
The best programs for home and pro use are "Cakewalk Sonar (versions 4 and up) for windows, and "Cuebase SX" for windows and MAC OS/X. As well as "ProTools" on windows and MAC. There are cheaper solutions for both windows and MAC such as "Ableton Live"
Personally I stay away from "DJ" programs such as "Audacity" because they do not give me the full editing scope I require. Sonar 6 works for me, but you should look into all of the alternitives to find whats right for you.