I read it's not a good idea to let your dog sleep in your bed, Alpha and all that, but who can resist?
Normally I start him on a pile of blankets next to the bed and in the morning will invite him in. Sometimes he starts out in the bed, and there have been very few accidents -- he can jump down if he has to. This morning the poor little guy puked in my bed, but he's fine. The sheets are in the wash now.
Right now I'm crate training him so he sleeps in his crate next to my bed where he can see me and watch TV.
Once he gets the hang of going outside we'll probably go back to sometimes in bed and sometimes not. At least he doesn't go crazy or bark his head off if I don't let him in.