Wit ht he help of a ladder I need to climb a tall backyard tree and wrap a rope around some tree limbs?

Safety Ladder

Use a weight tied to a string – throw it over the branch and pull the rope over with the string – don't need to climb at all

Good Luck

Safety Ladder

As Tahoe said, use a throw-line. Arborists use them all the time to set their climbing lines. Never free climb (climbing without fall protection), and never climb unless you are properly trained. You'll only end up damaging the tree or injuring yourself.

After you've got the throw-line over the limb you want it's a simple matter of attaching your permanent line to the throw-line (a sheet bend works well for this) and towing the line up and over the limb and back down to you. Then, using the running end (the end that was attached to the throw-line) tie a running bowline (do a search for both the sheet bend and running bowline, you'll find pictures and instructions on how to tie them) to cinch the line around the limb. Or you can attach both ends to whatever you are using as a seat. Repeat the process for your second line (if needed) and you're all set.

Beware that environmental conditions (sun, rain, etc….) will soon degrade whatever kind of line you use, so be prepared to replace it on a regular basis.