I have been doing well picking stocks but dont know if I should be holding the stocks that go up or selling them when I make a profit.
Your question is a good one and I can't give you the answer, but what I can do is help you make the decision yourself.
First, do you spend a lot of time watching the market and your stocks? If so then you could potentially call yourself a trader, in which case you can sell when you make a profit and then pick the stock back up on a dip.
On the other hand, if you happen to watch your stocks once a week just to see how they're doing, then your of the buy and hold category.
The second thing you need to ask yourself is how are you choosing which stocks you buy?
If your using fundamentals such as debt ratios, P/E ratios and other long term measures, the you are definitely in the buy and hold category.
If you use charting techniques and measures of volatility, and stochastic charts, then you typically are a short term investor who takes profits and buys on dips.
You need to decide for yourself how confident you are in the stocks which you buy. The more confident you are the longer you should be willing to hold the stock.
I suggest that every time you get into a long position (buy a stock) you look at the price history (charts) of the stock to determine where you think would be a reasonable place to sell.