Get something like this. You put the tea bags in the black thing in the middle (might want to cut the strings off any ones with strings with little paper things at the end), you boil water and pour it in, then you let the whole thing steep however long you'd like (usually like overnight or something...you can even make sun tea and steep it outside in the sun), then you put ice in on top of it once it's done steeping...if you let it steep a long time then the tea won't be hot anymore when you go to put the ice in (make sure you left room for ice lol), then you put ice in a glass then pour this over the ice in your glass (ice in the pitcher shouldn't get out through the spout once the top is on, or once you've had this in the fridge a day or two the ice will have melted anyway). Make ice tea with these things all the time and love them...we have like three or four of them lol.
Edit: If you ant the whole pitcher of tea to be sweet tea, then you're probably better off stirring in all the sugar while it's still the hot boiling water, before you leave it to steep, that way the sugar will dissolve easier in the heat.