So, I wish to build a computer soon and I would like to have the one HD for the Ubuntu OS and another HD for storage, but how would I set this up (so that when I install applications, etc. they automatically go to the storage HD, that way the OS drive won't get clogged up as quickly)?
You cannot easily install applications in an other than default place, what you can do is having user files on another partition.
I assume your a regular desktop user, and in this case the most logical "design" (imho) is to create 3 partitions, one for swap (of cause), one for the root (/) filesystem and one for your user(s) home directories (/home).
This way you can format/reinstall the OS without erasing user data/settings.
The process of creating this setup should be quite easy in the installer, just remember that the swap partition needs to be at least as big as your amount of RAM or the computer won't e able to hibernate.
