At Yahoo I gave some advice about investing in the stock market.

I'm thinking of investing in either city bank or Bank of America.  

I'm a second year teacher working in special education -my job is very secure, they can't find enough teachers to teach special education. After taxes and my monthly debts, I usually have $1,000 left over, which I just add to savings.  

-I have $17,000 in savings  
-I have $16,000 in student debt.  
- I have a car I owe $8,000 on.  

Can I afford to invest? If so, how much? 

I suggest 1st pay off your car loan (in full right now), then pay off your student debt as fast as you can, and then start investing the stock market. 

I do not recommend citibank and bank of america. There is a way to invest in the stock market safely. This is how I do it. I buy shares of corporations that have a very long history of raising the dividend every year, even during the worst recessions. I hold on to those shares for the rest of my life. If the stock market crashes I don't care because I'm in it only for the growing dividend income, not the capital gains. Using this method I can sleep at night because I don't have to worry about the price going up or down. And while this method of investing is boring it has the advantage of being both safe and it works. I can reinvest those dividends automatically for free (my online broker is Charles Schwab). This way my income grows without me having to do anything. These stocks are called Dividend Aristocrats. You can look that up to get some ideas. Also I recommend Seeking Alpha which has some good articles with some excellent comments written by wealthy successful investors. 

From another answer: "The trick is to find investment funds with Very Low Fees." 

I strongly disagree. Why pay "very low fees" when you don't have to pay any fees at all? Just make your own investment decisions. This is much better than sharing your retirement income with professional idiots. You can do it right with research which is easy to do with help from Seeking Alpha and sticking with the Dividend Aristocrats. Another advantage of avoiding the professional idiots is you have complete control of your investments. 

"Can I afford to invest?" 

You can't afford to not invest. You got to get to work at it, the sooner the better. 

"If so, how much?" 

As much as you possibly can every single month.

https://answers.yahoo.com/question/index?qid=20150823210516AAwWYFD