For my 2 cents, I can recommend the Tamron 17-50mm f/2.8 with vibration control, and the Canon EF-S 55-250mm f/4-5.6 IS. I paid $450 for the Tamron (Simply Electronics) and $190 for the Canon lens (Amazon).
Both of these lenses are good for stills, and I don't know about video as my Rebel XS can't perform the feat.
Take some classes as suggested, and go out and shoot everything and anything. I have started schlepping my camera everywhere, and looking for an excuse to photograph stuff. Go to events, feed birds, visit the zoo, line up your family members for mug shots. LOL Take pictures of the moon...
Take pictures of flowers, bugs, anything... and be prepared to throw out a lot of shots. I took 270 frames at the local nature center last weekend, and only kept 31 of them. Last month I took photos at a military rein-actor event and only use my 50mm prime. I took pictures of an indoor tennis match, and the lighting sucked, as did my 18-55mm kit lens (f/3.5-5.6), so I shot it all at 800 and 1600 ISO.
Most important is to have fun and enjoy your new camera.