Last edited Tue Aug 20, 2019, 08:15 PM - Edit history (3)
They make very inexpensive miter boxes that use a type of hand saw. If you aren't used to cutting mitres (especially with the cheap ones) then be prepared to use some caulking in the corners after it's all been installed.
Don't use glue, just nails hammered into the studs in the wall. Determine where the studs are before you place the baseboard, and make a light pencil mark on the wall just above where the top of the baseboard will be. That way you can see where on the baseboard the nails should be placed. Depending on the height of the baseboard (anything less than 4" ) two nails per stud should be sufficient (actually you will place one nail in the stud, and the other in the bottom plate that the studs are nailed to). Anything over 4" should have three nails, one in the plate and two in the stud. Use finish nails (the ones with the small heads).
Studs are generally on 16" centers, but they aren't always (depends on how old the house is, or if they had to make an adjustment for some reason). If the walls are sheetrock you can determine where the studs are by tapping on the wall. You will hear a difference in the sound over the studs and over the empty space between 'em. Over the studs it will sound more solid, more hollow over the empty spaces. They can sound quite similar, but I think you'll get the ear for it. They also make stud finders, but try the by ear method first, 'cause it's free. Not sure how it works for plaster because it is a more solid medium.
The bottom plate is simply a 2x4 or 2x6, the important number here being the "2." The 2x lays flat along the floor behind the sheet rock/plaster, so your bottom nail will go somewhere less than about 11/2" above the floor, 2x's are actually about 11/2"'s unless the home was built before about 1900, then they were the full dimension. Because the 2x runs lengthwise for the bottom plate you can put the lower nails in anywhere, but general practice is to keep them lined up vertically with the nail in the stud above it.
Baseboard will come in varying lengths. Just measure the walls and determine what lengths you need to avoid a bunch of waste. Best practice is to use some wood glue on the butt ends when you install it, but you don't have to.
Do yourself a favor and be sure to use the pre-primed baseboard.
Hope this helps. Someone will probably be along in a minute to tell me how wrong I am. 
PM me if you have any more questions.
Good luck.
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