I've invested in stocks as a hobby for the last ten years, so I'm no expert on this. But if you have contributed about $7,000 over the past ten years (like putting in $200 here and there) and your portfolio is currently worth $17,000 is that considered a good rate of return?
How about if you have limited types of securities--about 5 or 6 companies--at any given time? Is that considered being good at stock-picking or just lucky?
It's important to realize that any portfolio, if sufficiently diversified should track overall GDP growth, and anything growing via a percentage per annum is going to double eventually. (A good corner-of-napkin estimate is 70/the percentage = years to double). Just looking at your numbers, if you initially put in the full $7000, an increase to $17000 after 10 years represents a return of ~9.3% per annum (to check my math $7000*1.09279^10 ≈ $17000). Since you've been putting in the $7000 over 10 years the return is going to be a bit more than that, but it's not possible to calculate based on the information given.
A return of 9.3% is not bad (some rules of thumb: inflation is about 2-4% so if you are making less than that you're losing money, and 6-10% per annum is generally what you should expect if your portfolio is tracking the market)... I wouldn't consider that rate of return to be particularly amazing, but it's not bad either, as you've done better than you would have if you had invested in an ETF tracking the market. The stock market being what it is, you can't rule out the possibility that you got lucky with your stock picks. If your portfolio was low-risk, a return of 9%ish could be considered amazing, but given that it's about 5-6 different stocks what I'd consider amazing would be a return of 15%+ (to give you something to shoot for!) Either way, for your amount of savings you're probably better off going with a mutual fund or an ETF. The return might be slightly lower, but the risk profile is also lower than you picking your stocks, since the fund/ETF will be more diversified. (and it's less work!)
There isn't really enough information here to go on. Without knowing when you invested that money we can't find your rate of return at all, and it's important to measure your rate against risk. If you take on significantly more risk than the overall market but only just barely outperform it, you probably got a lousy rate of return. If you underperform the market but your risk is significantly lower then you might have gotten a very good rate of return. A savings account earning a guaranteed 4% might be a better return than gambling on the roulette wheel and making 15%.
Historically, the market's average rate of return has been about 8%. (Serakfalcon's "6% to 10%" is essentially the same number.) You should be able to get into that range for long-term investments with minimal risk.
"5 or 6 companies", unless you know a heck of a lot about those companies, is fairly high risk. If any one of those runs into trouble, a considerable amount of your net investment is riding on it. Of course if any of them invents the Next Big Thing you could hit it big; that's the tradeoff.
Diversification isn't sexy, but it buffers you from single-company disasters, and if you diversify across kinds of investment that buffers you from single-sector disasters. Index funds aren't sexy, but they're a low-cost way to diversify, especially if you go with a mix of funds in different categories (large cap, small cap, bond, international, real estate) or a fund which has that mix built into it such as a target date fund.
