I have worked in Heating and Cooling. I stress to make sure that if you close in the furnace and water heater (assuming gas appliances) that a professional check it out to make sure there is enough combustion air. I went on many CO detector alarms the winter after a basement was finished. It is really bad for the furnace but can kill you.
When my younger brother built his home, I wired it for him. I ran way more outlets than he and his wife thought they needed and at least two phone jacks in every room. I ran conduit to the phone jacks and left them open in the mechanical room. For phone wire, I ran cat 5. I had bought a couple of rolls on an auction for less than $20.00 per roll and still have a roll left. Ran this right down the 3/4 inch conduit to an outlet box and put a phone jack plate on it. In the furnace room, instead of splicing phone wires together, I bought a punch down block. Then I ran the phone line from the demarcation block to the punch down block, again cat 5. It allowed me to easily hook up any phone jack in the house with any of the 4 pairs of wires in the cat 5. Also ran cable in the same manner.
This came in handy a few years later when he began a home based business and turned one bedroom into an office. The phone company guy came to run in the 800 number line, the business line, the fax line, and the computer line. What he expected to take half a day took less than one hour because all the jacks and cables were there and the punch down block made it easy to change for multiple lines. Save several $$ on that alone. Plus, with all the extra outlets, he had enough power to function without having more installed. Much less money to do it while building than after the fact.
I have been involved with numerous remodeling projects. I echo the choice to use a professional drywall guy. I have seen projects where the pros bid less than the cost of buying the sheetrock, mud and tape alone, and the drywall is usually done in three days, ready to paint. Hard to beat it.