We do not allow trading of in game items for real cash, unless within the bounds of the RMAH when it is launched. You can make people aware of your RMAH trades by posting a picture of it, they can then search their regional RMAH to find the exact item if they wish, for example. No trading trough paypal or anything similar.
Do not bump your trade thread more than once every 3 hours. If there is interest in your item people will see it and bid, you won't need to bump it endlessly. If you break this rule you may be subject to a 6 hour suspension from the forum and if you continue possibly even a ban.