How do I setup my fields for a tumblr-like blog My blog has different post types, e.g. full blog post, quick status, quote, image post, how would I go about it? Is the logical way to setup a single Matrix Field with each block representing a different post type? Is there a better way of doing it?

Stating the obvious for clarity. A full blog post would have the usual stuff (title, body, image). Status has just content without a title, it's just a quick note. Quote has text and quote author and link, again no title.
I definitely would avoid using a Matrix field to add each of these types, as they'd all belong to a single entry, which isn't what you want to do (it’d get really unwieldy, really fast!).

What you're looking to do is use different entry types in your blog settings. Each entry type can have a different field layout, so you could then switch between each.

Here’s a blog article that covers the exact thing you’re trying to do.