I would have a good gunsmith mount the rings and scope. Ask if he/she will do it in front of you so you can see how it's done and ask questions.
The purpose of the rifle will dictate the optics. A good general purpose scope is a variable magnification 3x-9x with an objective lens in the 40mm range. The larger the objective lens, the brighter the image. However, larger also means heavier and greater height above the bore. When choosing rings, you must pay attention to the size of the scope tube. Generally, scopes have either a 1" or 30mm tube and the diameter of the rings must match this. Rings come in varying heights, usually expressed as low, medium and high. The height of the rings is driven by the size of the objective lens (Sometimes referred to as "the bell" of the scope) and the size of the shooter. The larger the objective lens, the taller the rings, because the must be a bit of space between the bottom of the objective lens and the barrel. Taller rings can present issues for smaller statured shooters because they may not be able to get a consistant cheek to stock meld due to the height of the mounted optic. Mounts for modern bolt guns are usually one piece or two piece affairs. Many mounts are of the Weaver variety that have slots that the ring mounts onto. Whatever mount/ring combo you buy, make sure they are compatible with each other.
Hope that helps a bit.
Mike