I have to agree about McAfee - it's really ineffective and difficult to remove all elements of it whe you replace it with another software. Removing Norton was also a pain, as it seems to infiltrate everything on your computer once installed, so you need lots of patience if you switch.
I've been using Avast! Home edition (free) and find it to be great. Here's a helpful site link with forums for all kinds of computer/software questions:
http://www.computing.net/
You can search any software for your operating system and all the faqs will be listed, or ask specific questions in the forums.