Most bicycle wheels are mounted to the frame using a quick release mechanism. As the name suggests it is for easy removal and fixing of wheels in emergency or competitive situations. The quick release has 6 parts, a long skewer with thread on one end and a clamp lever on the other, two conical springs, a bolt and a cam follower (a cam follower is not present in all designs). The order for assembly is as in the image. (small end of the conical springs facing inwards).
This guide helps you check if the quick release is installed properly on your bike after any kind of service. Especially fixing a flat from a highway or rural puncture shop. Following this guide you can ensure that the wheels are fitted safely on you bicycle.
Step 1: Place the axle bolt in the dropout (grooves) of the frame correctly. Check by spinning wheel before you tighten any bolts. If the wheel touches any frame part newly or if the wheel spins tighter than before, you should remove and reposition the wheel into the dropout again. It might be rubbing against the brake pads (disc or V-brake)
Step 2: Hold the nut of the quick release tightly and spin the lever clockwise while holding it in the open position. You should turn it till you have it in a position where pushing to reveal the CLOSE marking is only possible with a little effort from you. Not too lose, not too tight. A good rule of thumb to establish the correct tightness is to tighten it all the way and then loosen it back by a full to three quarter turn and trying to close it.
Note: Do not force the quick release shut. The force from a single thumb finger should be able to close the lever. The marking saying close should always be visible when locked.
Always have the levers on the non drive side of the bicycle. That is mostly how your manufacturer set it up. Maintain it.
Do not overlap the lever onto frame parts like the fork in the front or the seat and chain stays at the rear. It makes is harder slide your fingers in to open it the next time.
Crank Tip: If you do install it overlapping any of the above frame parts, slide a rag cloth through the gap and pull on the rag.