If you are only making 30k/year between 2 people, a good investment might be trying to learn on teamtreehouse.com, for $25/month you can learn on there, and I know you said you don't have time, but as little as 1 hour a day would help. I've heard they help get people jobs after you finish enough of their courses as well.
Another option might be trying to get a job as an apprentice of some kind, you'll still probably get paid and you'll also learn skills. One example, they are hiring Pre-Apprentice Linemen at my local utility starting at $12/hr, but if you do well then after 1-2 years you can become an apprentice linemen which makes more, and then a few years later you can become a lineman and make a lot more.
I've heard you can buy ETF's of Vanguard for as little as $50, but when I went to start my Vanguard account I had to put $3000 down to get into Vanguard total stock market. I think the combined Vanguard fund can be started with only $1000.