HI Kokopelli. As stated correctly below, always consult your Accountant. Here's something to consider. The IRS allows an (IRC 121) "exclusion of gain from sale of principal residence." I believe this would pertain to you.
I believe it is the exclusion of taxes for a single person on up to $250K of profit from the sale of your principal residence and double that amount for married couples. Any remainder would most likely, be taxable but the purchase of another pricipal residence should mitigate most taxes to a large degree. Again, consult your accountant or a tax professional as I am not one.
Investment property is another story and I believe the (IRC 1031) 1031 exchange for like kind property is your best course of action. There are specific time-frames for finding another property and closing to be aware of and yes, a qualified intermediary (not just an Attorney) is the best professional to talk to. Check this site for 1031 info: http://www.legal1031.com
Don't go FSBO, consult a local Real Estate professional. I'm also happy to give you a referral. Good luck with the sale of your property.
Joseph C. Hastings
Prudential Douglas Elliman Real Estate