For me personally, scooby1962's videos on Youtube were really helpful. Great advice on building muscle without doing crazy stuff, not requiring a gym and almost no equipment.
i discovered scooby through a friend of mine a long time ago and his tips really helped getting me started with weight lifting. i have lost all my back problems since then. just remember, as long as an exercise feels good, it is unlikely to hurt you. i had to learn this the hard way, i pushed too hard on an exercise, ignored the pain and was left with a typewriters cramp, not so great if you are in front of a computer typing all day long. so start small and build your way up.
For the record, though, scooby's pretty sweet & his videos are for sure an interesting, if kinda goofy, resource.