Investing Zero to One
General investing advice and information.
Basics
I generally start with the Bogleheads theory of investing. This involves investing in a few ETFs or mutual funds. For example, a 3 fund portfolio. I use Schwab funds, but any with low expense ratios will suffice.
An import piece is figuring out the asset allocation for each fund. The simplest setup is just use a target date fund, picking a typical retirement date. SWYGX is one such Schwab fund with a target retirement date of 2040.
Target date funds are not a good idea for a taxable brokerage account. They are mainly best for a 401k or IRA account. See this thread and this SEC filing for why.