To check for gas...Put a small amount in your test jar and cover the top with your palm. Shake the wine pretty hard. When you release your hand, if there is gas, it will pop like a Coke bottle would. It won't come out when bottled.
"Pretty sure" will get you bottle bombs. You must be absolutely sure its done fermenting and stabilized.
Other than that, fill up so that there are 2 fingers worth of space under the cork and don't lay the bottles down for a few days to allow the corks to set in place.
If you are going to store the wine for more than a year, add a half campden tab per gallon to protect the wine from oxidizing.
I'll also agree with William...you must drink wine while bottling wine!
Just because something CAN ferment, does not mean it SHOULD be fermented.