Your first questions to answer are:
Heating method. Since you are in a basement, electric is probably the best bet for indoor. Amp needs will be determined by size, so next question. If you go natural gas, make sure you are well vented.
Batch size. 10 gal is probably appropriate, and you can get 15.5 gal pots (old kegs) on the cheap if you look around.
System type. 3 vessel (MLT, HLT, Kettle) is most common, but there are some 2 and 1 vessel systems floating around that can save space.
So, assuming you want to do 10 gallon batches with electric, your brewery infrastructure is going to need:
1x 240v, 30A GFCI to run a 4500-5500 watt element; two if you are looking to run both HLT and Kettle at the same time.
1x 120v, 15A GFCI to run pumps, radios, ect
Decent capacity exhaust hood and fan to vent steam
About 2'x6' table/bench space for the brewhouse
Some space for grain storage
Freezer space for hops
Fridge space for yeast
Some space for 'stuff', buckets, siphon tubes, etc
Some place to ferment and condition