If you want to roll up your sleeves and learn a new discipline, but just as a hobby, you might get the best information density from a commercial outline, like Emanuel or Gilbert's.
Probably more info than you could ever want, but those usually contain abbreviated outlines in the beginning, and more detailed outlines in the back, so you can expand to the level detail desired. It could even serve as a general reference aid (with the caveat that textbook law is rarely good law, it's usually superseded by local regulations or more recent precedents - it might just get you in the ballpark).
You'd get a deeper understanding of some of the key debates in the development of these areas of the law by reading the case law referenced along the way.
There's some benefit from seeing how the law handles contracts differently from torts or criminal law, and trying to figure out why, so you could turn to those subjects once you've mastered contracts. That's essentially the law school approach.
If you just want to make yourself a more well rounded citizen or think deep and interesting thoughts about social order, then probably pick a major case in Supreme Court law every week or so to read through and ponder. Read the dissents as well, the dissents are really crucial to making it clear why these were nontrivial questions.
Here are 50 highly cited SCotUS cases (from a few years back, but not a terrible list to start with): http://heinonline.blogspot.com/2009/01/most-cited-us-supreme...
You could listen to the oral arguments for many of these over at the Oyez Project:
But that's really of secondary interest to the actual opinions.
If you just want to be more savvy in commercial transactions and court cases, you probably need a tour through the Uniform Commercial Code, and to learn some Federal Rules of Civil Procedure. Those are just seemingly endless lists of abstract rules though, not sure there's an easy way to make those more accessible. That's what keeps attorneys employed, I'd recommend avoiding unless you're considering law school.
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