When your pinball machine arrives at it's destination, you will want to find just the right spot for it. You will need approximately a 3 foot by 8 ½ foot area. Why eight and a half feet? The machine is about 56" long (4 feet 8 inches) and you need about two foot of space to stand behind the machine to play it (a total of about six and a half feet). We need the full eight and a half feet in order to remove the playfield glass. You may not need the full eight and a half feet all the time but it should be available with minimal fuss.
An other important consideration is lighting. The pinball machine should never be in direct sunlight. Sunlight fades the colors of the cabinet, playfield and plastics. Room lighting should be indirect. You will not enjoy playing your game if you have glare on the playfield or backglass. Ceiling lights can be troublesome, lamps work best. And dont forget how much fun it is to play your machine in the dark, so keep that in mind too.
Once you have found the right spot you should take some time to level your machine. Your manual will have a suggested incline for the playfield but before you worry about that, check to see if your machine is level from side to side. You can get close with a level placed on the glass but you will have to take the glass off and level the playfield in order to get it right. Most levels are too big to fit on the playfield. I bought a level that is made to hang on a tight string. It's only three or four inches long and didn't cost much at all . Many pinball parts sources have levels or incline meters if you want to go the "official" route (plastic incline levels cam be found at Wal-Mart).
For the incline, most playfield's are set between 6 and 7 degrees of incline (check your manual). The incline meter is the tool of choice but why bother. Incline depends on your personal taste in game settings. Its your machine, set it up the way you enjoy it most. Start out with the 6 or 7 degree incline and suit to taste. A six degree incline is approximately one and a quarter inches per foot, seven degrees is approximately one and one half inches per foot. Divide proportionally and hold your level with one end touching the playfield and measure the distance down to the playfield on the other end with the bubble dead center. Another solution is to cut a triangular piece of cardboard indicating your incline (one foot long and one and three eighths tall) and check to see if the top edge is level when sitting on the playfield.
Pinball machines weigh between 250 and 300 pounds. Lifting to turn the leg adjuster is difficult. I have found that you can crawl under the machine and lift it slightly on your back and adjust the screw. Use your best judgment, it's your back. Remember, it's always a good idea to get some help. Don't lift any higher than you have to, you don't want to tip the machine over. One other thing, the nut on the adjuster goes under the leg, not on top. Loosen the nut, adjust, then snug the nut up to the bottom of the leg to lock it in place.