I've been teaching my self C++, slowly but surely. Everything I try to program is just mediocre, and much simplier to use something already made. How long does it take before I can start programming useful decent programs?

I think it depends on what kinds of projects you try to learn how to do. I greatly enjoyed a class where I learned how to write a proxy, malloc, a simple shell, and a few other interesting/useful projects all in C. The book from the class (written by the instructors) can be found at Amazon as well as other places. The book also comes with a list of assignments very similar to the ones that I did.
However, in another class I wrote things like a basic search engine, but still found most of the concepts pretty simple and boring. So if you're not interested in systems programming (the understructure of how computers work) you might not find the book as useful as I do.

Hi!

I believe WindAndWater is basically true. I learned C++, Java and Python just by writing interesting software. I mean, I didn't even know, how to write a program in C++ but I tried to write a server application.
And I succeed. And my second such server was great.
It's not worth learning from books, I suppose. They're just for help (for reference).

The same went on with Python. I wanted to write an IRC bot because I was interested in it. I did not write any Python programs before, but during the developing of this program, I learned it.

There are some useful links to use when programming:
http://www.google.com/
http://www.koders.com/ => this one is the most useful, I believe. It's a search engine, but it searches in the source code of opensource projects.
http://www.cplusplus.com/ref/ => C++ reference
http://www.sgi.com/tech/stl/ => STL reference

http://code.dreamincode.net/snippet74.htm => essential, I believe. Describes how to use private data members of an object from "outside".

etc. You can use google to search for what you want.

kl223

I have learned C++, Java, Lisp, PHP, Assembly all through courses in high school and now college. I lot of them is just learning the basics by doing stupid problems in books and then struggling through harder more realistic problems. One of my projects for a class was to write the game Hex. Take it we didnt have to do a GUI for it, but in the end you have all the background you need to add a simple GUI just by changing the pring and input functions. Basically, once you feel like you know the basics (linked lists, trees, search algorithms, classes, data abstraction, and a few others i cant just name off the top of my head) then you should try to make something that interests you. Write a basic text game with some ai. Then teach yourself some GUI and add that to it.