I'd do 90% stocks, 10% bonds, assuming you don't need the money until retirement. You could go down to 80% or up to 100% (I actually do 100%, but I also do individual stocks plus index funds).
S&P 500, a broader-market fund (3000-5000 companies in the US market, to get smaller businesses too not covered in the S&P), and some kind of global fund. Depending on how your 401k is held, you want to take that into account when allocating the rest of your money, and be careful because a lot of 401k plans have horrible funds (high expense ratios).
You might want to look at Roth IRAs too --it's a post-tax contribution, but never taxed on the gain or withdrawal. There are income limits to contribute, but there's a backdoor by contributing to an IRA (not income limited) and then converting it to a Roth.