Sticking ads on a WP 101

I’ve got a series of questions that I sense must be asked all the time, and so I’m wondering if a tutorial exists that covers most of it.

Questions like:

1. I’d like to insert those text Google Ads– but how and what pages do I alter?

2. I’d like to insert portait banners on the sides of my site or in the links bar. How and what page(s) do I need to alter.

3. I’d like to insert those tiny tags in my footers somewhere. How and what page do I alter?

I’ll go look around the Wiki. Any help, as always, very appreciated.