Confession: I don't clean paint brushes. I use one brush for an entire project and then I toss it. I've been using this same navy paintbrush for a month now. By placing it in a zip lock bag each time I use it and squeeze all the air out I'm able to keep reusing it.
I chose 10 of the old shelves that were in the best shape (since I removed 2 bookcases I could be picky). I think the prior carpenter may have been drunk when he cut these shelves because none of them were even close to being the same size. I sanded them and rolled on 2 coats of Benjamin Moore Simply white in semi-gloss using a foam roller (gives it a smooth finish that you can't get from a wall roller or a brush).
After caulking every seam I painted all the woodwork. It took forever but it is amazing what paint can do to brighten a place up.
Remember all the seams and raw edges where all the old and new pieces met on the side of the shelves?
My solution for that was to box out the bottom part of the shelf using 1"x1" strips of wood. The box shape matches the rest of the room while hiding the mess.
Finally on to the last and the fun part - Loading all the new decor into the room!