Everyone is going to have their own opinion and 2 cents about what you should do, so I'll add mine to the mix.

First of all, most importantly, you'll never find a better investment than yourself, up to a point. Whether it's education, new skillsets, saving time, starting a new business, etc, you're likely the best investment vehicle you have. Don't read this too literally, it's not a science, but I'd add it to your thinking. Ask yourself regularly how you can invest in yourself and grow your earnings.

Second, related to the above, I think it makes sense to spend a bit of time optimizing and automating your finances (I'm a fan of "I Will Teach You to Be Rich" by Ramit Sethi, despite the scammy title), but from then on, spend 20% of your energy on keeping expenses low, and 80% on growing your income. You can only cut expenses so far, but income is essentially unbounded.

Third, I would spend a lot of time educating yourself on finance and investing. As has already been mentioned here, the /r/financialindependence subreddit and the Bogleheads forums are both great places to go from here. Read lots of books (both of those places will have recommendations), blogs, listen to podcasts, etc.

Fourth, in terms of the stock / bond market, I'd recommend just doing index funds with Vanguard. I could go on and on about the reasons, but basically it comes down to it likely being the best way for you to get the highest returns in the public markets. You can't beat the markets in the long run, and almost all the non-index-funds out there can't either. Vanguard popularized index funds, they're owned by their investors, and they have the lowest cost funds available.

Fifth, if you're likely to get overwhelmed by options, just do a lifecycle fund to start with. It'll handle all your asset allocation and rebalancing for whatever your time horizon is. If you're really likely to get bogged down, consider Betterment or Wealthfront. You'll pay a bit more in fees, but in return for convenience and a fancy dashboard that makes you feel good :) Better than never getting started!

Sixth, I'm bullish on real estate in good cities with long-term growth, but I'd recommend you have a decent pile of cash, start slow, and invest for cashflow. Keep in mind that buying investment real estate is just buying a small business. It just so happens that for a bunch of reasons, you can borrow 75% of the purchase at pretty favorable rates, and it's lower risk than buying many other types of businesses. It is not passive :) Biggerpockets.com is a great community for learning more about real estate investment.

Seventh, going back to the first point, beyond public stocks / bond and real estate, you could also look to invest in private companies, either your own, as an angel investor, etc. There are some crowdfunding sites that have popped up recently for doing angel investing in startups, investing in real estate, etc. You can also look at things like Prosper or LendingClub, where you're lending money on a marketplace to other individuals. Lots of options.

My advice would be to focus your energy on the big three that people have almost always used to build significant wealth: public stocks, real estate investments, and your own business. The others are exciting and interesting and can work, but generally carry a lot more risk.

My own (unscientific) approach is to keep them all below 10% of my networth. Same with picking individual stocks, if you're into that.

Hope that's helpful!