RAM (alamadingdong)

Well to start off it’d probably be wise for me to note that I’m pretty computer hardware illiterate. I don’t know really anything about all the peices that make them work and all.

First off what I want to do is upgrade my RAM from 256MB to 512MB
I have a few questions though.
Is that going to create a very big boost in speed or not really? My computer has been bogged down like crazy lately, so I need to get it going a little faster.
How do I know what type of RAM I have (ie DDRAM, SDRAM, RAMALAMADINGDONG, etc.)
I have a Dell Dimmension 4400 that I got like 2 years ago if that helps the knowing what kind of RAM I have process.

Anyhow, any information would be fantastic.