Bedbugs are little bastards that are hard to kill, can live in cracks in walls and furniture, and it is notoriously difficult to make sure you got rid of them all. Usually the only thing that kills them is heating the entire apartment and its contents to a temperature of 120F for about 2-3 hours. This dehydrates the bugs and their eggs, killing them.
The other option is to lower the temperature inside the building to 0 F for a duration of 4 days, which is much harder to achieve than the heat option.
Professional pest control services should be called for whatever you attempt. Using a can of Raid around beds and baseboards just won't cut it. Take all clothing out of the home and to a laundromat. Wash everything, preferably using hot water for long wash cycles. Do NOT bring the clothes home and put them back in closets or drawers. Instead keep them in sealed black plastic bags while the treatment is being done.
Items like knapsacks, luggage, handbags, etc should also be isolated and steam cleaned if possible. Again, wrap in plastic and leave it out of any infected home until proper treatment has been done.
If your mattress and box spring are old, I'd say toss them out. Get a new set and leave the plastic on them until after the pest control treatment. For small items (teddy bears, wooden jewelry box with felt lining, etc) that would fit into a black garbage bag, wrap them up, seal them, and leave them sitting for a few days in a sunny spot. The heat will build up inside and hopefully bake the critters and eggs that may still be in there.
Get rid of carpets if possible, or arrange to rent a steam cleaner to try and to cook any bugs, especially close to the edges of the room. Vacuum all areas of the affected rooms, getting rid of the vacuum bags immediately after use, or emptying and cleaning the unit if it does not use a bag.
Not bringing bedbugs into your home in the first place is the best prevention to getting an infestation. So if you live in a self-contained house, try to avoid bringing home clothing from second hand stores without having them cleaned first. Don't grab an old sofa or love seat from the side of the road, or even a desk or cabinet, as the bugs can live for weeks in cracks in the wood, with eggs hatching only 6-10 days after being laid.
Of course, living in an apartment, you are often at the mercy of how well your fellow tenants take care of any problems they might have had. Treat 8 out of 10 apartments, but leave the other 2, and a month or so later, you'll be seeing your bloodthirsty friends again.