How do I frame for interior doors?

I am currently trying to frame out a couple of doors in my basement. My question is the size? Should the opening be the actual size of the door or should I be leaving a certain amount of space around the door opening (sides and top) to accomodate the jamb. Is it difficult to build a door jamb myslef or shoul I get the premade system and cut it to size. Also the doors are both irregular sizes, 32X76 and 32X73. What perhaps unforeseen difficulties might this present.

I see the light at the end of the tunnel on this project. Thanks for the help.

 

Normally a rough opening is 2" wider in each direction to leave room for jambs, to shim it plumb and a spuce under the door for flooring. I like prehung doors, but your odd sizes (in height) may be a problem. You normally trim adoor from the bottom, but that will put your doorknob so low it will look odd. You may need to buy slab doors (flush, since six panel doors will look odd cut down so much.

Also hollow core doors will have another problem--when you trim them you'll loose the blocking that holds the outside edges together--you'll have to replace it.

If mortising hinges, drilling for locksets etc. sounds daunting to you, consider bifold doors (like you often see doubled up on closets).