You can find here several "-testing" isos.

This means that they're not stable, even they can be outdated and it's possible
that there's a newer stable version in the "-stable-iso" directory.

The -net ones are "network installs", so it will not be useful for you if you
want to do an offline install.

From the CD ones, usually only the first and the second CD is enough, download
all of then only in case you don't have an internet connection nor a DVD drive.

DVDs: the second DVD is optional, download only in case you don't have an
internet connection.