I'm trying to install the "WinRAR" one but it doesn't seem to want to compile.

Is there an easier to use Archiver that supports RARs?

There's a shareware rar program for Linux, which must be registered within 40 days of use if you are going to keep using it. This is written by Martin Meredith. It is in the Ubuntu multiverse repository. You didn't say what distro you're using, so I can't give you distro-specific info.

There's also an unrar implementation by Ying-Chun Liu, which is in the universe repository. The homepage is here.

majority of distro come with rar now. try install your native one. Like ubuntu using: sudo apt-get install rar

I dont know if you've been here or not, http://www.rarlab.com/rar_add.htm .
Thats where i got the one i use. It was easy to install and easy to use.

apt-get install unrar rar

I'm in Ubuntu.

drael@Teletraan8:~$ sudo apt-get install rar
Password:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package rar is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package rar has no installation candidate
drael@Teletraan8:~$
drael@Teletraan8:~$ sudo apt-get install unrar rar
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package unrar is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package unrar has no installation candidate
drael@Teletraan8:~$

doesn't work :/

Enable the universe and multiverse repositories.

I've been able to download most packages okay... what are the APT lines for those repositories..? I can't edit the source.lst file... says I do not have permission :/ How do I make it so sudo is always on in the file browser?

Look for lines ending in 'Universe' and add 'Multiverse' after it....and don't forget to uncomment the line if it's commented.

https://help.ubuntu.com/community/Repositories/Ubuntu

Cool thanks that worked... unfortunately the package itself isn't great :/ Is there not something the equivalent of Winrar, where I can rar and unrar stuff?

You could try to run winrar using wine. Integration with your file manager will be ugly though.

Once you've got the rar and unrar programs installed, ark and/or the gnome archive program should use them and give you a nice GUI.

You're right that the rar programs on Linux aren't great. This is mostly because it's not a format which people on Linux are using very much.