The Wheel of Fortune is extremely handy to build up items. Every day you log in you get a free amulet.
It is possible to get all the materials for your gear from the wheel but it takes months to build them all up. If you have the patients and don't have the money to spend on coins eventually you can get all the materials you need from the wheel of fortune.
There is a huge range of items you can get from the wheel, in fact you can get nearly every item in the game from the wheel, except some such as Excalibur which cannot be won on the wheel.
Coins can occasionally be won from the wheel. From 10c (the lowest amount) to 1000c (the highest amount). However coins are very rare. You could expect to win the 1000c maybe once or twice a year so if you do win it make sure to invest it in good items. My advice is to buy a number of excalibur's (to speed up troop training), and a number of advanced teleporters.
Advanced teleporters can also be won from the wheel however these are also extremely rare, in my opinion as rare as the 1000c so if you think you can get by using advanced teleporters just by winning them from the wheel you are mistaken. You will have to buy them if you are going to teleport a lot.