i don't think a realtor is necessary, but a real estate lawyer to draw up contracts is.
They could also provide you with the necessary disclosure forms.
The most important things to remember are:
1) Never appear to be trying to discriminate against any protected class of people. You can certainly mention facts - ie, "news source rated the grade schools as 5th in the state" but don't say "better for childless couples". Even if it's true - it could be construed as discriminating against families, which is in violation of federal law.
2) Whatever you are required to disclose - DISCLOSE. Put it in writing. I was able to successfully sue the former owners of our house because they claimed that the house had no water problems. Turns out I found a receipt for water proofing buried behind a drawer in the basement cabinets - and the basement flooded when the water proofing failed. The former owners were required to pay for the lost items, cleanup and the new water proofing system. Don't let it happen to you!
3) It will take a lot of time. Just like being your own general contractor will. If you don't have the time, don't do it. Hire a realtor. If you do, and you are willing to spend the time doing things the right way, you can save some money and possibly enjoy yourself.