trouble uploading linux

I have two questions about Linux:

I would like to know what version can be good for a beginner, here are the details of my pc
Intel dual horn, 1.8 GHz, 512 RAM. I heard talk of ubuntu, and I do not know if it's good.

So I try to download on this site
http://www.ubuntu.com
but the audit md5 does not stick, so I try repeatedly, ie 20 times, without success, I began to despair, because I really want to put myself a linux ...
thank you for your help in advance.

Hi,

Ubuntu will be perfect for you, it's a very good distribution
For the md5, tries to download another mirror (those factors are generally fast)

http://www.ubuntu.com/getubuntu/download

Simply download the iso, serious image and launch the facility.

What is ISO? thank you for your reply .

What you download is a picture CD,. Iso