Any tips to be up to date with recent opening theory?
As noted by Penguin chess engines aren't really a good tool to use to learn opening theory. You could create an opening book based on the opening you want using chessbase, or polyglot and practice the opening against the engine. The Fritz interface does have some training capabilities for learning openings, but that isn't tied to the engine so any uci engine, such as stockfish, could be used for that.
More common would be to use a chess database and filter it for games within an opening line, and play through the games.
Another possibility is to use software specifically made for learning openings, such as Chess Position Trainer, and Chess Openings Wizard.
Usually, computers are not very accurate in the openings. I'd suggest using a good database of grandmaster games like Chessbase or Chess365. If you're trying to prepare against somebody or against a variation I'd recommend using Chessbase while running an engine. For example:
- e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 a6 5. Nc3 Nf6 6. Be3 e5 7. Nb3 Be6 8. f3 h5 9. Nd5 Bxd5 10. exd5 Nbd7 11. Qd2 11... g6 12. O-O-O 12... Nb6 was the position I was preparing against.
The main line goes 13. Qa5 Bh6 14. Bxh6 Rxh6 but in many games White just gets a worse position. This is unsatisfactory, and Stockfish 6 found an improvement.
If you're curious, go check out how white gets a forced advantage.
I would disagree with the other two answers here. Computers are an excellent way to study openings. I think Kasparov would agree with me because he did all of opening preparation with computers once they got strong enough.
Computers can quickly show you all the viable lines of play in an opening. An opening book will usually only focus on two or three key variations. Thus, you can get a much more thorough understanding of an opening with a computer. More importantly, the computer will show you why particular moves are bad, which opening books often do not do. The books assume everybody plays perfectly all the time. In reality players will often make serious mistakes, but unless you know how to punish those mistakes, the book is not very useful.
I find computers very good for giving the "feel" of an opening. Some openings are so sharp you die if you make any little deviation from perfection, but others are very tolerant, and you might have a choice of 15 different moves, all OK. A computer will quickly identify the plausible moves so you can tell if a line is sharp or relaxed. Often what you want is an opening that is relaxed for you (easy to play), but sharp for your opponent.