One knot you could use is an Italian friction hitch aka a munter hitch or HMS.
I'd recommend abseiling with a figure eight though, or if you're inexperienced use a descent device such as a Petzl I'D.
Make sure you have the correct rope though!
I tied a knot in the rope.
A type of knot use to make a loop at the end of a rope. Made by unravelling the end of twisted multicord rope and plaiting the unraveld ends back into the rope.
The most secure knot to use when tying up a horse is called the Quick Release Knot. It is very simple, and one of the easiest to learn. It is handy in the way that you can simply grab the end of the rope and pull, and the knot in the rope will release immediantly. For info on how to tie this knot, try here: http://www.newrider.com/Starting_Out/Getting_Ready/quick_release_knot.html
A dolly knot
You seem to be describing a noose. The cowboys use a lariat.
One of them.
You can take each ends of the rope and as you tie it slide your hands to the opposite side of the knot!
use the rope
Keep proper posture. Receive massage. Stretch often. Exercise. Avoid sitting too long at a computer/in a car/etc. Stay hydrated. Get adequate rest. Allow your body time to relax.
Use C02 to propell the pellet
To tie a rock to a stick, you can use a strong rope or cord. Wrap the rope around the rock and stick multiple times, then tie it securely in place with a knot. Make sure the knot is tight to ensure the rock stays attached securely to the stick.
When tying down a large tent the best rope to use is any nylon rope. Nylon rope doesn't soak up moisture like a rope made of natural fibers, but it has just enough give to hold the tent in place.