What you are discussing is the basics of money management.
How much do you risk? When should you take your profit? The two most important questions any trader will ever face.
Perhaps
this little series of videos over at YouTube will help you out in this regard. It's plugging myself a little bit - but quite honestly, I've never seen a series that covers it in the same way. The manner that's made all the difference in both my trading, as well as my investing. Making money in the markets isn't about being right. It's about knowing how to manage the money in your account to your trades.
I know a trader who just blew out 3 accounts last week. The ironic thing is that this guy was right 85% of the time.