As for what to do with the rest of the money after the roof, I would consider several things.
1) Are you planning on staying in the house long-term?
2) Are there structural integrity issues that need to be addressed?
3) How is your home different than the others in the surrounding area?
DH and I did some renovations to our home in Mississippi this past year prior to selling it. We spent $20K and got the following:
--Master Bath: paint, flooring, new air bathtub ($1800), new bathtub surround, and new shower...all done in travertine, new lighting, new mirrors.
--1/2 Bath: new ceramic tile, new fixtures, new mirror, new lighting, new window treatment, paint
--upstairs Bath: New ceramic tile, paint, new fixtures, new mirrors, new cabinet pulls, new shower curtain (LOL, I added that because it cost nearly $100!)
--Living Room: new fireplace--covering the 18 ft. high x 6 ft. wide brick fireplace with sheetrock, pillars on the sides, new mantle, travertine tile, and a new fireplace screen
--Kitchen: new pulls, painted cabinets, remade island, new gas line, new gas cooktop, new sink and plumbing fixture, tumbled travertine backsplash, and granite countertops
--Master Bedroom: new carpet, new paint, new window treatments
--plus new paint in laundry room, mud room, stairways, playroom, upstairs office and downstairs office
--new french doors on office
Now. We did every bit of the work ourselves except for the granite countertops, which cost $4000 of the total $20,0000 budget. We did all the work for cosmetic reasons and because the house was looking dated for an up-scale neighborhood. We sold the house at a $108K profit after owning it two years.
If I had $50K and your house, I'm sure I could work much better miracles than anyone HGTV ever thought about hiring. I think it all comes down to learning what you can do and budgeting your money correctly.
Your costs for labor are going to be high in the Northeast, so take that into consideration when planning your renovations.
Good luck!