Plus-X is a fine film that has been around for a long time. If you are going to develop it yourself, start with Kodak's recommendations for processing, and work from there. More than likely, you will make some adjustments as you learn more. If you want to do some B&W photography to try it out, without developing the film yourself, you might be better off using Tmax400CN or Ilford XP2+. These can be processed by a color lab.(posted 8869 days ago)A yellow filter is used a lot outdoors. It will slightly darken the blue sky and make it look more "normal." Without filtration, blue sky tends to wash out.
Books: O'Brien and Sibley: The Photographic Eye.
London and Upton: Photography
Horenstein: Black and White Photography
Many community colleges offer a basic photography course. The quality will vary somewhat, but with any luck, many of your questions will be answered effectively through demonstration, assigned practice, and critiques. Read some, and then get out and take a lot of pictures!
Some more information on what experience you have had already with photography would be useful for futher advice from others.
If you just can't wait, set you camera to f/11, 1/125 of a second, go out on a sunny day,and take pictures! That setting is with the filter. With no filter, start with f/16, 1/125.
Using a light meter, set the "ASA" at 125, although you may end up setting it at 80 or so as you gain more experience with Plus-X.
Have fun!