I need some explanation on how to uninstall the applications that i install
should I keep the source that I installed?
should I just go ahead and delete the files in

what is the clean and the right way to remove programs?

/usr/bin
/usr/lib
/usr/local etc.. of the related file?
/usr/local/lib

and what good the [I]makepkg[I] does? is it any useful?

well I am a newbie too so please somebody explain thanks in advance

Basically... for Linux. There is no 'correct' way to uninstall a program if you installed from source.

Just delete all the associated files, and you're good to go.
If you installed via RPMs, goto the Unistaller deal within the Control Center.

Also. I see you're running Slackware, and are a n00b.
I recommed using either RedHat or Mandrake if you'd like to learn Linux.
Both are much more user friendly.. for Beginners such as yourself (and me.. sorta)

yes that is what is usually said about slack.. but u know what?
i first installed redhat on my computer when I first started linux like 3 years ago..
then last year I wanted to try out the slack and for some reason I switched back to rh a cpl months ago cuz slack was giving me headaches ..well sort of..

and What I felt after installing redhat was that I found my self in a disguised windows under linux name...

and after my 1st boot right after the installation
1- eject the cd tray
2- put in the slack cd
3- close the cd tray
4- reboot
5- what a relief even seeing that all text based screen instead of the redhat's takeover image... wow.. I Feel Goood! man