Painting - Roll or Spray?

I just purchased an old home (built 1885) that needs some TLC. One of the projects I plan to do on my own is repainting the entire interior...2300sf of living space. The former owners smoked and all walls are still the original plaster with mostly a flat latex finish (2 of the rooms have an glossy look to them, though).

I need advice on what my best course of action would be, given that I don't have a lot of time to dedicate to this project...maybe 3-4 weekends...and that I need to prime & paint all ceilings and walls. Should I spray? Are there sprayers that work better for interior work than others?

Also, is there a primer that can both be sprayed on and will stick to any existing finish (oil or enamel paint)?

Thanks in acvance for any help!

First of all, clean the walls and woodwork with TSP or its equivalent. Given my experience with my 60+ year old plaster walls, I would prime with Zinser to really seal everything well. This will cover almost anything. I recommend rolling and brushing. A first time job inside is no time to learn to spray. I used a power fed roller to do my house. I had two weeks to repaint the entire inside, after work hours.

Spray takes a lot of prep time. I would only spray if you want everything (and I mean EVERYTHING) the same color and finish. Zinser is definitely a good suggestion on priming, you never know what they have on those walls, an easy way to test is to take some Goof Off (or M-1 Remover, same thing) and LIGHTLY rub each wall with a rag/paper towel, if it comes off on the rag, then it's latex. This is true for Latex Flat, Satin, or Semi-Gloss. You can use this method to test all the walls (especially the glossy walls, they may be an oil-based) and the trim, if you plan to paint it also. Make sure you prime the ceilings good too, as this where most of the yellowing from smoking occurs.

Good Luck!