I dont seem to have much space on my computer and i am not sure why. I dont have that much on it. How do i free up space?

There are two causes for a hard drive filling up.

1. It has been filled with media/content by the user. This is the most common cause.

2. It has been filled by a runaway process by the system that has not cleaned up. Less common.

In response to cause 1.

Regaining Hard drive space:

The easiest approach is to assume that the space has been filled up by your own files: documents, but also includes, videos you have downloaded, photos, music, pdf's, downloaded software. As these files have either been created or downloaded by you, you will know where to find them and these are the things to move or delete.

So look in your Movies folder, Documents folder, in the iTunes and iPhoto applications, for excess movies, photos and music that you can move onto an external drive, or burn to a CD, and then delete.

After you delete anything, remember to empty the trash to recover the space on your hard drive.

In response to cause 2.

Open the console application and look at the system.log for any repetition of a process that may indicate a log filling up perhaps. The information here tends be be rather vague.

In addition, download some utility that gives an easy overview of your hard drive like Grand Perspective,

download http://grandperspectiv.sourceforge.net/

and see if anything jumps out at you, as taking up an unreasonable amount of space.

Grand Perspective is a visual diagnostic application only, it is not designed to clean anything up. You have to manually act on any information it provides.