This article will give you a step-by-step guide to becoming a millionaire by investing with Vanguard. I will detail the steps to opening an account, choosing your investments, and setting up automatic contributions.
Keep in mind that similar brokerage firms will offer a very similar value proposition. I personally use Vanguard because I am a fan of their investment options, but Fidelity and Charles Schwab (to name a few) offer very similar options that will achieve an effectively identical result.