Screen Window size

When I bring up an application or connect to the internet the window is much smaller than my actual screen size even when I click on the + to make it bigger. How do I increase it's size to fit the screen? Thanks

Drag the bottom left corner to the bottom corner of the screen. As you have just found out, windows in OS X don't work the same way as they do in Windows.

If it really bothers you, you can try Megazoomer. I haven't tried it but it may satisfy your needs for full screen windows. Note though that it only works for Cocoa apps and will therefore not work with all OS X apps.