J.H.
First things first: Start watching/DVR ing all design shows. Spend some time discovering what YOU like in design/decor. Then you can concentrate on getting the look/feel you like for the best price. (Design on a dime, Designed to Sell, Bang for your buck-iffy, Divine Design!!, etc. Plus there are serveral shows that just re-do bathrooms.)
Regarding the bisque colored shower stall: that can easily be changed to white by those company's that come in and re glaze. We did it a couple of years ago in a house we were moving from and I was completely WOWed by how great it looked. (We were covering up a pink tile and a pull plastic shower stall.) If you choose to not do this- it is not like you are working with pink or blue- bisque is very neutral. I like the suggestion of a shade of green. Green is very hot right now. You could also introduce a shade of grey- which is also very hot right now and looks great with bisque- this would give you a more modern look.
The return on a tile in your bathroom over linoleum will be huge. Look for a local discounter. Ceramic tile does not have to be expensive. Use an online calculator to determine how much tile you need for each space and then go shopping. You could find "left over" batches that are big enough for your job but would not work for other people, thus a better price. You do not have to do all the bath's with the same flooring. To make the spaces look bigger use a big tile and lay them on the diagonal.
Love the idea of painting the vanity's white. If one of the rooms is a powder room consider giving it a more designed look; paint the vanity black or dark brown and dress it up a bit. Bed, bath and Beyond, Hobby Lobby, Micheals all have inexpensive accessories that can make a bathroom look great.
Be VERY CAREFUL using paint in the rooms with no natural light. All of them will read MUCH brighter in the room. (I had a living room painted a warm creme color- decided to use the extra paint in a bathroom with no natural light and it looked yellow! It was a pretty yellow but the color was completely different from my sun drenched living room to my bathroom. I put black & white toile in the bath and it looked great.) So buy sample colors before committing to a gallon. Ask the guys at Sherwin Williams their opinion- they will usually give you a safe color.
Also, the colors that will work in a house with 10" ceilings are different from the colors that will work in a house with 8" ceilings- these get less light so a less saturated color might sit best for a person new to design.
For shower curtains: Bypass shower curtains and look at pre made drapery. Then you hang a plastic liner inside-clear- and dress the outside of the room with the drapes. The higher you can hang them the better- depends on your ceiling height. (This also apply's to your window treatments. Hang them just below your molding, or if you are going with premade curtains 102' or 96' off the floor. It will make your rooms look bigger. This also works with hanging the curtains on the outside of a window to make it look bigger. Have the curtains just barely sit on the egde of the window molding to creat the illusion of a bigger window.)
I think it is great to go ahead and do this all as you can afford it because the house will be much easier to sell in 3-5 years PLUS you get to enjoy how great it looks.
BUT start with watching several hours of TV shows- jot down what you like and see where that gets you.
Good Luck!