What does Type IAA mean on this ladder?

Type IAA is the highest duty rating in the Werner line, good for 375 lb including the user and tools. That is heavier than Type IA (300 lb) and Type I (250 lb).

How high can I safely reach on the 8 ft model?

The ladder is about 96 inches long, so it reaches roughly 8 feet of working length. Plan on standing no higher than the top few rungs, which puts comfortable reach around 10 to 11 feet.

Is fiberglass better than aluminum for this ladder?

Fiberglass rails do not conduct electricity, so it is the safer choice for electrical work. Aluminum is lighter and cheaper, but it conducts current.

Does it stand on its own?

No. It is a single-section straight ladder that must lean against a wall, pole or other stable surface. For free-standing work you need a step or platform ladder.

How much does it weigh and can one person carry it?

It weighs about 20 lb, light enough for most people to carry and set up alone. The length, not the weight, is the main thing to watch when moving it through doorways.