Pednurse, as Mike stated, most have a 50lbs limit for each bag - max checked bags, without extra charges - two.
You also have the measurments of the bags to consider.
Checked baggage - Outside measurement must not exceed 80 inches (width, height ,thickness added together).
Carry-on baggage - two - one to fit under your seat or in the overhead, and the other - Example: purse, laptop. Measurement of largest bag - 9"x16"x19".
Also, ALL airlines prohibit ANY type of liquid, jet or spray items in your carry-on bags.
Hope this helps. Might be a good idea to check with your airline, just to be sure.