G.T.
We have a family bed, which we just sort of grew into with our first son because I got really tired of getting up to nurse him all the time. I love it. When my oldest son began sleeping with us regularly (not until he was one year old, in fact), we took the bed (mattress and box springs) off the bed frame and put it directly on the floor. That way, falling is not such a big deal. If that wouldn't work for you, I'd recommend a bed rail.
My oldest son is now five and sleeps in his own bed, which is in our room, right next to ours. Many people freak out about our arrangement, but it seems natural to me! We don't use our bedroom for anything but sleeping, really, so why not share and use the extra room for something else? Anyway, he's been happily in his own bed since he was four. We moved him there when we moved apartments, and it he didn't complain about it even one bit. (Big moves are good time for other transitions, as well.) Before that, we had his twin bed up next to our queen-sized one, but it was my husband who always ended up on the twin bed.
I have a two year old, too, who sleeps with my husband and I. We have a bedtime ritual whereby, after we read them books, I lay down with my older son and my husband lays down, in the big bed, with my younger son, and we turn off the lights and often all four fall asleep. My older son will go to sleep on his own, and does sometimes when I have a lot of work to do, but he complains about it. I'm sure there are many who would criticize our laying down with them to get them to sleep, but we all love that ritual and wouldn't trade it.
Once the kids are asleep, we get up and get down to housework, etc. My husband usually will move my youngest son to the crib, where he'll sleep until about 1-3 am, when I get up and bring him back to our bed. Sometimes, my husband just leaves him in the bed, which is fine, except that he'll wake up then as soon as I go to bed, wanting to nurse. For naps, when we don't want to nap with our two year old, we lay with him until he's asleep and just leave him (in the big bed). In his whole life, he's rolled out of bed maybe twice, and since the bed's been so close to the floor, no big deal (he didn't even wake up, once).
Anyway, that's what's worked for us. It's a very personal decision, of course, different for everyone. I would advise that, if you want to get your child sleeping on their own, do it as soon as possible. The earlier in their lives your routine is established, the better it seems to work. From what I've heard from other mom's, it won't be done without crying. There is a book we read, way back when our oldest was about nine months old: The No-Cry Sleep Solution by Elizabeth Pently. It has some good tips, but it didn't work for us.
Good luck