The enumerated powers of Congress make an impressive list. Make sure you take notice of the final paragraph, which essentially says "and anything else that you need to carry out what you have explicitly been given".
In spite of the breadth of the subject here, I think for the most part it is pretty self explanatory. With the exception of the Militia. I have included an entire page for that subject alone, which you can access from the button on the bottom of this page.

Legislature - Powers of Congress

Lay and collect taxes	Establish Post Offices
Pay Debts	Provide Patents
Provide for Defence and general Welfare	Constitute Inferior Courts
Borrow Money	Define and punish Piracies
Regulate commerce including intra-state	Declare War
Establish uniform rules for Naturalization	Raise and Support Armies
Establish uniform rules for Bankruptcies	Provide a Navy
Coin Money	Make rules for the government of Armed Forces
Fix Weights and Measures	Call forth the militia
Punish Counterfeiting of Securities and Coin

Organize, arm and discipline the Militia, with states retaining choice of Officers, and training.
Govern the District of Columbia and any properties purchased from the states for Federal Needs.

Make all Laws which shall be necessary and proper for carrying into Execution the foregoing
Powers, and all other Powers vested by this Constitution in the Government of the United States,