I want a program that will store everything you type. Can you help me out?
 

Is there such a program?

That runs in the background and stores everything a person type?

This is for my own personal use, I just want to know who is using my PC whenever I'm not around.

search google for a keylogger

Yikes, that would fill up quick for me.
Kind of like an ICQ log right?

Yep... That's kind of....

Is there any way I could find out something someone typed on my PC sooner today?

Everything you type into messenger etc is logged. I busted a guys girlfriend for cheating on him by decrypting these files. Of course everything you do online is also recorded etc, and yes Evidence Eraser etc does help but your tracks are still there for anyone who knows what they are looking for.

not unless you had a keylogger installed then

Get a keylogger. Here is a safe place to look:

http://www.illmob.org/files.html#keyloggers