Is Bootstrap another framework that can be used? Is it recommended, or are Canvas & Genesis better?

Treehouse has a blog tutorial about using Bootstrap with Wordpress here :
http://blog.teamtreehouse.com/responsive-wordpress-bootstrap-theme-tutorial

Bootstrap is not a WordPress theme so in that sense, it's not in the same category. It is a very popular web development framework though, and if you still want to work with it you'll have to either do some manual labor and incorporate the CSS/JS/HTML of Bootstrap into a WordPress theme(you can use the guide mkmk mentioned for that), or find a WordPress theme that's already based on bootstrap that you could see yourself working with.

Bootstrap is a framework for design, other examples would be Bourbon and Foundation (my personal favorite). Genesis is a theme building framework, it comes with a lot of built in functionality and a very specific way of coding/templating, other examples are themes like _S, FoundationPress, and JointsWP. Canvas is different in that it is a theme that uses the Options panel to do customizations to layout, color, and typography.

With that being said, use whatever framework that works best for you. Bootstrap and Foundation are the two most popular design frameworks, and Genesis has a rather huge following in the WP community. There are a lot of themes out there that come prebuilt using those frameworks, and you always have the options to use a skeleton theme like _S and use Bootstrap with it.

Thank you for the replies. There is so much to learn in this crazy field of web development! I will look into all of these.