Scott's 5 months old!

Well today my baby is 5 months.  He has grown so much and is so much fun to be around!  He can almost sit, roll over from both sides, eating cereal and some solid foods, and he is now playing longer and longer with his toys!  He is such a snuggler and loves to be held.  He is starting to love James more and more and instead of cringing when James would enter a room, his face actually lights up!  My only complaint is his sleeping schedule!!!!  He basically doesn't nap, unless you are holding him - and if you do put him down he is awake within 15 minutes.  At night he is doing better and sleeping about 3 hours at a time, nurses, and then going right back to bed until about 6 am.  The sleeping thing has been really hard especially since there is James that needs SOME attention.  We haven't given up on putting him down for naps and even though he still wakes up, we keep trying!  At what age do you let them start crying and soothing themselves to sleep?  We have tried it a couple times and I think it has worked like twice but the other times I have given up and pick him up and then within 30 seconds he is asleep!  Crazy boy!!!!  But we sure love him!