The Debian website isn't what I'd call, user-friendly
http://cdimage.debian.org/debian-cd/7.4.0/amd64/iso-dvd/
There are 3 of the same named iso files (with the exception of the numbers at the end)
and 2 "update" things
Which one should I download?
Download 1, when I used debian I used this, files can always be pulled via http
If you have fast internet and don't mind downloading your packages get the netinstall. You will also want testing not stable, and maybe even upgrade to sid unless you are running a server