Whenever I add a bed or bedroll I can't activate it to sleep in it. Is there something else I need to do?
Make sure you're using the objects under FURNITURE and not under STATIC. The ones under STATIC are just dummies.

but what about using things from already created mods from other people and then saving that? like if i opened the cs and loaded my own mod with active save file, and loaded another mod from someone else i had downloaded such as mmm monster mod, and wanted to add those monsters in to my own mod in various places, would i just drag them into rez positions in my mod like i would original oblivion monsters? and then save it to my active file and they would be save on my mod now?here more to that?
When you want to use stuff from another mod, load them both into the CS with your mod as active. Then double-click on the object from the other mod in the object list, click Edit Base, and change the ID. Click OK. When asked if you want to create a new form, CLICK YES. That part is super important. NOW you have a copy of that object in your mod, and changes you make to the copy, and any references to it, will stick in your mod.
Just make sure if the object has a script attached that you either remove it or duplicate it also. If you need to duplicate it, copy the whole thing into a new script with a new name - renaming the one that's there won't make a new one.