I don't know what any of this means. And remember, I said a small, monthly amount. Small.
There are funds called "ETF" (exchange traded funds) or "Index Funds" which attempt rather than actively manage and "pick" stocks in the fund, try to match the broad-based sectors of an economy, or in the case of some of the big Index funds, try to match the S&P 500 index as a whole.
Generally they're very safe funds due to diversification, and also lower in fees than most of the actively-managed mutual funds. They're great for passive investors who don't know what they're doing--and possibly better than the returns of active investors who think they know what they're doing lol.
XLK is a fund which attempts to be a broad-based technology sector specific fund. So if you think technology is going to be a generally bull market over the next 17 years (duh!), it's probably a good sort of fund to look at. XLK of course is the stock ticker symbol for that fund.
CD also suggested a health-care sector ETF, which again is assuming that health care in general is going to be a bull market or at least a stable market as the baby boomers retire and become old folks. Probably pretty safe place, with upside.
Finally, he suggested a dividend ETF. Most people think that you make money in stocks by the price going up and lose it by the price going down. That's somewhat true in the "hot name" stocks, but a lot of giant companies reward their shareholders via dividends instead. The companies are large and stable and profitable, and instead of growth they use those profits to pay their owners [shareholders] a quarterly dividend. A dividend ETF will retain and reinvest those dividend payments, which is how your portfolio grows. This would be likely the safest of the three options, but with the least upside.
So you diversify your investment into growth (tech ETF), potential growth (health care ETF), and stability (dividend ETF).
Make sense?