To build muscle mass, you of course have 2 lift at least 6 days a week (rotating muscles). If you want to put on serious muscle in 8 weeks than you need to go on some sort of supplement. Basically it goes like this:

• Creatine --- Least amount of risk but the least effective for instant weight gain.
• Andro --- "Mini Steriods", some risk (some argue just as much as regular anabolics) but it will put some muscle on you.
• Anabolic Roids --- There's a risk, but if you go on for 2 months and cycle nothing will happen to you. But there is always the danger of getting addicted to the shit (or more likely, addicted to the result they give you, and you will go the way of Ravishing Rick Rude).

In addition, you'll probably want to eat 5-7 meals a day (chicken, steak, potatoes, etc.). Lots of proteins and stay away from carbs. 2 Protein shakes a day, at least, they're cheap. You probably want to do less running during this portion cause running prohibits muscle gain slightly and its much easier to tone when you have the muscle than to stay toned while you get the bulk.