You can use a rule to quickly find the center of a board's width without dealing with small fractions. Lay the rule across the width, keeping the scale's zero mark lined up with one side. Then angle the rule so that an even number lines up with the opposite side. Mark the board at half the distance. You can also find the center by drawing an "X" diagonally across from one set of opposite corners, then across from the other set of opposite corners. The exact center will be where the lines cross.
When you are fastening two pieces of wood with screws, keep the pilot hole through the top piece slightly larger than the diameter of the shank of the screw. This will allow the wood screw to pull the two pieces of material tightly together. If the pilot hole is too small, the top piece can climb the threads of the screw and leave a gap between the two pieces.
On certain projects, you may be required to work with brass screws. While the brass results in an attractive finished project, it is a soft metal that can easily be scratched or damaged. The solution is to use your drill to create a pilot hole, then drive a regular steel screw of identical size into the hole. After the hold is created, remove the steel screw and replace it with the brass one.