Breaking co-sleeping????

With my first, he slept through the night at 11 weeks, in the crib, no problem. Hasn't looked back. He is a great sleeper. So when our second was born, I thought he'd be the same way. I just had him sleep with me to start, because I had to get up and care for my three year old. I needed to get some kind of rest. Now that he's five months old, he won't sleep in his crib. Here is the problem:

We put him to bed in his crib asleep. He wakes screaming at 11pm. I go soothe him, put him back to sleep and in the crib. He usually wakes again between 1 and 1:30 am. I am so exhausted at that point and fearful that he'll wake my three year old with his screaming, I just go get him and plop him into bed with me. He goes to sleep immediately and wakes at about 6 or 7 am. I need to break this habit asap. I don't want to have a one year old in bed with me. I want to break this while he is still "baby" enough to let me without a huge production. Anybody have any tips or books they've read?

Please understand, I'm not knocking co-sleeping. Plenty of happy families do that with great success. It's just not for me. I really want my bed to myself and my kids in their own beds. Any advice will be gratefully appreciated!!!