New to Macs. Just a few questions.

[aerok]

Do have anything to back up this claim?

Once the battery is charged, the power adapter draws little or no electricity from the outlet. So how would this ruin the battery? It certainly causes less harm to the battery than a continuous cycle of full draining and charging.

From Apple site:

For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time.

http://www.apple.com/batteries/notebooks.html