Investment walkthrough (401k, IRA, taxable accounts, etc):
Most people, when they think of investing, think they have to predict which stocks are going to take off, which points in time are the best to buy low, and which points in the time are the best to sell high.
I'm here to tell you to ignore that shit, because nobody can do it reliably and consistently, especially over the long run. This is a concept called "market timing," which is a fancy-pants term for "trying to predict what the market will do in the future." There are various reasons why this is a bad idea, but I won't get into it in detail here. For the vast, vast, vast majority of people, trying to time the market (as a general strategy) will make you underperform the method I'm about to describe (over the long term). Yes, you could predict something correctly and become wildly rich, or you could be wrong and become poor as fuc. There's no need to take on this kind of risk to become financially stable over the long term.
So what should you do?
1. Don't time the market.
2. Diversify your portfolio.
3. Buy low-cost index funds (that approximate the entire market) and use a reasonable asset allocation. More on this later.
4. Buy these funds as often as you can stand it.
5. Ignore what the market is doing. Keep following step 4, no matter what.
That's it! Not very interesting, is it? The funny thing is that over the long run, you will beat most strategies. You won't beat them all, but the people who do better (in terms of market investment) are generally the ones who took big risks -- risks that could have easily gone against their favor all the same.