Secure the bottom front (tack) of the mainsail and jib to their respective shackles on the boom and the bow of the boat.
There will be a small line (outhaul) attaching the rear corner of the mainsail (clew) to the end of the boom. Pull it so the foot of the main is taught, and cleat. This helps the main sail have a smooth shape for the air flowing over it.
Hoist the mainsail by pulling down on its halyard all the way until it stops. It will be flapping around (luffing) like crazy, but that's OK for a short period of time. (Excessive luffing will drastically reduce the life and durability of the sail).
The leading edge of the sail (luff) must be tight enough to remove folds, but not so tight as to create vertical creases in the sail.
There will be a cleat in the vicinity of the halyard where it comes down from the top of the mast. Cleat the halyard. Using the jib halyard, raise the front sail (jib, genoa or simply the headsail), and cleat the halyard off. Both sails will be luffing freely now. Sails are always raised mainsail first, then the jib, because it's easier to point the boat into the wind using the main.
2. Adjust your heading and sail trim for the wind.
Sailboats cannot sail directly into the wind. As shown below, the red zone in the diagram indicates a "no go" zone when under sail. To sail to windward, a sailing vessel must sail about 45-50 degrees off the wind and change direction by tacking (or zig-zag).
Turn the boat to the left (port) or right (starboard) so it's about 90 degrees off the wind. This is known as a beam reach.
Pull on the main sheet (trimming) until the sail is around 45 degrees away from straight back (aft). This is a safe place for the main while you trim the jib.
You will start moving and tilting (heeling) away from the wind. A heel of more than 20 degrees usually indicates that you're being overpowered. Releasing the mainsheet momentarily (breaking the main) will lessen the amount of heel, and you will return to a more comfortable sailing angle of 10 to 15 degrees.
3. Trim the jib sheets.
Although the mainsail is hoisted first, it is the jib that is trimmed first. There are two jib sheets, one for each side of the boat. Pull on the jib sheet on the the side away from the wind (leeward side). This is the active sheet while the other is called the lazy sheet.
The jib will form a curve or pocket; trim the sail until the front edge just stops luffing. Keep your hand on the tiller (or helm) and stay on course!
4. Trim the mainsail.
Let out the main sheet until the front edge just starts to luff, then pull it back just until it stops.
If you or the wind hasn't changed direction, this is the most efficient place to set the sails. If anything changes, you have to adjust them in response.
You have just entered the world of the sailor, and you will have to learn to do many things at once, or suffer the consequences.