Sounds like you're on the right track;
1) Set yourself mini-projects of ever increasing difficulty (Hello World, Lottery Picker, Etc Etc)
2) Find a good book or two that contain exercises and can be used as a reference.
It's been about 15 years since I read it, but I seem to recall that the Stroustrup book wasn't exactly the friendliest of the "how to learn..." C++ books. You may want to spend some time on Amazon and do some comparisons.