after putting in the 'subject', i 'clicked' for similar threads and found my story w/ubuntu is not unique. i'm(and will continue to be) a 'Slacker', but thought i'd try ubuntu as it sounded like they might be getting it down and i had a machine i wanted off the internet-big mistake for ubuntu.i haven't been able to get anything installed-no plugins, no sage(math software), nada. anybody has any advice, i'd appreciate it since, for my purposes, i've got a fancy animated brick-guess i'll just have to hook up to the repositories. thanx.

If you mean you can't compile programs from source code, that is because you need the build-essential (and possibly the kernel sources) packages to compile from source in ubuntu. Get the machine online and set up your sources-list either by editing /etc/apt/sources.list or by checking the sources in synaptic:
http://www.psychocats.net/ubuntu/sources
Then for installing software:
http://www.psychocats.net/ubuntu/installingsoftware