hi, im starting back up after a couple years of numerous injuries.  im going to start at my house (so i dont embarass myself) rather than the gym.  i have an old soloflex, free weights, full power block dumbells, a slideboard, cycleops spinning trainer for my bike, a heavy bag and a speed bag.

im 40 years old, coming off shoulder reconstruction, groin tear and 4 rt ankle reconstruction surgeries.

i bought fitday (even though i have no clue how to use it effectively), but would really like to start something and do it right.  i was thinking of doing the slideboard and spinning everyday, but would like to know what exercises i should do to minimize the risk of injury and maximize muscle gain/fat loss.  could someone give me some ideas?  what about supplements?

YOu need to concentrate on conditioning and injury prevention.
I would see what your Physio says about progressing on.
cycling is great and also with the arms for your upper body injury, slide board is great for your lower body injury and these will both get some cardio going, I would keep up with some of the drills the physio gave you, if they did.....post op plyometrics.
Also look at your diet.  Later you can start a mild weight training mixed with your conditioning which you will never  want to stop, that should be a constant from now to grave if you wish to really heal and keep healed those areas.
Linda