Yea use fraps its the best one by far.

Well there are quite a few programs that you can use, but keep in mind that if you are recording any game you might encounter some "Lag" while playing and recording at the same time.

Here are some names more common around the Recording world of Youtube:
Fraps-(i personally dont like this program heard bad reviews of it)i believe there is a Free Trial version.
Ezvid-It is Free I had this program, its good for Starters
CamStudio-Free screen recording program which records all the screen and the audio activity on your computer and create industry-standard AVI video files.
Camtasia Studio- I dont think this is Free, i haven't used this program in years. But it is a very good program. Has lots of options and comes with a editing program.
Dxtory- Love this program. Records vary well. Plenty of options to tweak your recording. Can split Audio files from your game play so you can edit later.(I recommend this program, its not free but its worth it)


This is just my opinion of these Recording program, its totally up to you

Hare are the Recommended specs for minecraft:
INTEL CPU--Pentium 4 3.0GHz
AMD CPU--Athlon XP 2600+
GeForce 8600 GS
Radeon HD 6320
1 GB GD RAM
Win Xp 32(but Windows 7 is preferred)
DX 9
1 GB space

But if you want to Record games better i would Upgrade to more RAM(4-6 gigs), Plus a Fast SSDs hard drive.

If none of the above work for you, there's another one which isn't very popular but is very good in my opinion.
It's called [ Register or Signin to view external links. ] .