The type of deed your son gets from you is important as to what type of warranty he will be able to grant to the party who he will sell to or better yet what kind of warranty the buyer will require, a Quit claim deed merely grants any title you "may" have "if any" and it does not carry any warranties with it. In most cases a buyer and or lender will require that you provide them with a warranty deed which carries warranty protections against adverse claims on the property. If he gets a Quit Claim from you, you are off the hook but he now is faced with trying to guarantee a title. Usually to avoid being entangled in any potential legal claim against the property the buyer and or the seller get title insurance protecting them from adverse claims. Once your son receives the deed from you and the deed is recorded he has the right to convey the property to another.

As to the gift and tax issues you need to check here

IRS: Selling your Home Publication: http://www.irs.gov/publications/p523/index.html and http://www.irs.gov/publications/p523/ar02.html

IRS: Home Sale Exclusion rules, publication: http://www.irs.gov/newsroom/article/0,,id=105042,00.html

IRS: Estate and Gift Taxes:
http://www.irs.gov/businesses/small/article/0,,id=98968,00.html

IRS: Tax information when buying a home: http://www.irs.gov/publications/p530/ix01.html

IRS: Deductible costs when purchasing real property:
http://www.irs.gov/publications/p551/ar02.html#d0e2000

IRS: 3.6 Itemized Deductions/Standard Deductions: 6. Real Estate (Taxes, Mortgage Interest, Points, Other Property Expenses): http://www.irs.gov/faqs/faq3-6.html

As to creating an instrument from your son to you, you might want to create a real estate/land contract however if you're son does not create the same thing when he sells to another then you will be paid off at closing when he sells even if the instrument is a note and mortgage instead of a real estate/land contract.
Buena Suerte