Deleting Applications?

How do I go about deleting applications? I am new to the forums for starters (sorry guys)... Plus this is my first Mac, I haven't had to delete anything off of it yet and can't quite figure it out.

My issue: I have two versions of Safari on my computer. Version 4.03 or something like that, and the new 5.02. I know I upgraded to the 5 when it came out and I had assumed I was running that since then. Turns out I've still been running 4, and was having an issue with the "New Tab" not working. Thats when I noticed I wasn't running 5. (if you follow me?)... I just redownloaded 5 b/c i thought it would overwrite the 4 version, but it didn't, now I have two Safari's and when I do a spot light search 2 show up as well with no indicator as to which is which.

If it matters, I am running Snow Leopard with everything up to date (at least I think? considering I thought this was...)