How to connect radiators to the pipes

I am assuming that the radiators you want to hook up are designed for hot water? If so you will need to run two pipes to each radiator, one for supply water one for return. Radiators work well on a monoflow Tee installation ( I suggest you Google monoflow tee intstallation). Valve the supply side so you have some adjustment of water flow to regulate the amount of heat it will put out. From your boiler you will need to install a main supply pipe all the way around the perimeter of the house (in the basement). I suggest a 1" diameter copper pipe. Then you will need to locate your radiators. Install a supply tee in the 1" pipe and go up to your radiator with either 1/2" or 3/4" copper pipe. Install a valve in this line to regulate flow. Connect to the radiator using the correct fitting. On the return side, connect to the same diameter pipe as the supply and take that down to a monoflow tee installed in the 1" copper pipe. Make sure you face the tee correctly or you will not get flow thru the radiator. Because there are different methods to connect radiators, this is just a suggestion. Google the net for other suggestions, talk to a heating professional and study prior to installing or it will cost you money and aggravation.