Exercise rotation for conditioning

Could someone let me know if there is something I need to know about this...I've been doing some reading and I think the idea is to do weight training on various muscle groups, working the muscle to the point of fatigue, then having a rest day. On rest days, it's okay to do cardio, yoga, pilates or just plain old rest. But one should not do weight training two days in a row without some sort of rest in between.

Have I got it right?

That's what I've always heard.  For weight training, you should leave the space of a day between workouts to allow the muscle time to rebuild/repair itself.   

I would agree; however, when I asked my trainer, he said generally as long as you have a minimum of five hours of rest between, you're okay.
(not like I'm doing it ever five hours!)

You can do it day after day but it's best for your muscles to have a rest...you should also give your body at least one day of rest per week.  It's to allow the muscles to grow and develop...sorta like sleep for the body!