This tutorial assumes that you know how to safely operate your power tools. Always refer to manufacturer instructions if you are unsure how to use your tools.
Any wood worker needs to take a board from lumber yard or their local sawyer and make this board a uniform thickness, length and width. This board needs to have all four edges square to each other. This is referred to a milling a board four square and is a pre-requisite to any wood working project.
This is best accomplished by using a jointer, thickness planer, miter and circular saws and a table saw. In this example we will mill a board 30" x 4-1/2" x 5/8" with all for edges square to each other.
Step 1: Rough cut your stock
Rough cut your stock to 30-3/4" x 4-3/4" and maintain same overall thickness. Start by selecting a piece of stock larger then your finished size (obviously) and use a framing square to square off one end of board. Be sure end isn't checked (cracked) and if it is square board off just beyond where cracks end.
Make cut using a circular saw being careful to make a fairly square cut. Now measure 30-3/4" and square off board using your framing square make second cut same way you made first. Be careful to cut on waste side of line.
Step 2: Rip to rough width
The table saw is best tool for this cut. Set rip fence so it is 4-3/4" from blade and set height of blade so gullet of teeth is same height as stock. Following directions included with your table saw start blade and make cut, being sure to use a push stick.
Step 3: Truing one face
Now that your piece of stock is rough size needed it is time to true up one face. This is best accomplished with jointer.
As always with jointer it is advisable now to take more than 1/16" per pass. Taking more wood per pass will overwork machine and give results that are less than optimal.
Analyze board to determine direction of grain and whether there is cupping. It is best to place cupped face down since it will site better on jointer table. Run board through for a couple of passes until you have a uniform face free of voids and dips.