I'm installing Tiger on a partition, what is the minimal space I allocate for it? My files will be run with an external HD. Would Tiger run well with 20GB after installation?
20GB is more than enough, I ran Tiger and many applications and user files on my iBook G4 with a 27GB HDD. 10 to 12 GB should more than suffice, and if you de-select the languages and printer drivers during installation you might end up with a 7GB installation.
Actually, Tiger needs only ~2GB in an utterly minimal install - no printer drivers, language translations, or extra stuff like X11. It's Leopard that takes up 7GB in a minimal install.