In the bicyclist world there is a list that should always be kept in mind when performing bike maintenance and before a ride. It is called the ABC check.
The first letter A, stands for air in your tires. The air pressure in your tires can be checked by simply squeezing the tire or bouncing the bike up and down. If the tire surface yields or if the bike does not bounce very easily this means that you probably need more air in your tires. Tires that have the proper air pressure are rock hard. If you have an air pump but you have no idea how much air pressure your bike needs you can find this information on your bike tires. The second letter B, stands for brakes. You can test your brakes by squeezing them while astride your bike and pushing your bike forward. If you cannot move your bike this is a good thing. Remember to test both your front and back brakes separately. The third letter C, stands for crank/chain/cassette. The crank is what is used to propel you forward when you are on your bike. This is the pedal drive chain apparatus. The chain is the roller chain which is attached to the sprocket which is the circular gear at the base of the pedals. The cassette, on most bikes is at the center of the back wheel. It controls your gears and keeps your chain in line. The crank should not wobble when you move it in a circular position. The chain should move smoothly along. The cassette should not impede the movement of the chain. The forth letter D, stands for drive chain which has already been mentioned. It stands for the whole pedal apparatus. The fifth letter Q, stands for quick release. The quick release is the metal handle that is found at the center of each of your tires. It is part of the bike frame. Make sure the quick release is tight. Also make sure both of them are in the correct position. If you are riding through a forest or anything really if you quick releases are situated forward or toward the front outer part of the wheel they could get snagged on something.
To clean your chain you should use mineral based chain oils. When your bike is not in use it should be stores in a dry place so that your bike won't rust. The absolute best place to store your bike is in a bike shed. In a shed your bike won't rust and it won't be tampered with or stolen. Bike sheds come in different sizes and shapes. You can place one outside of your apartment or garage.