How to keep bedbugs away?!?!?

We have been living in a apt for 8 months now and we have been infested with roaches and now our couch has bedbugs! Our bed doesn't have them but I REALLY want to keep it that way. It is up on a frame and I have put vaseline around the wheels because I heard this prevents them from climbing up onto the bed. I also heard spraying pure ammonia can help, but I have an 18 month old and don't know if thats safe. Any other suggestions to keep them out of our bed and maybe even eliminate the problem entirely? Any help would be GREATLY appreciated. Thank you and God Bless =] P.S. we aren't financially able to move right now, and I already called the city to come and inspect.