You can go about training a couple ways...
You can top, either straight topping or FIM (where you purposely leave bits of the terminal shoot instead of removing them cleanly, resulting in more new shoots at that origin).
Or you can bend or tip the main stalk so that it still has that terminal cola but the side growth is more exposed to light. If you bend the tip down very low, almost making a horseshoe shape out of the main stem, the side growth that is higher than the terminal bud WILL grow faster than if it had been left alone.

The big idea of training is to make the plant the optimal shape for your setup. You should almost never need side lights! The exception being in a super micro grow with flouros... and IMO that isn't even worth the effort!

If you go look in the logs, and under 'foxysox is back in the game', there are a few different shaped plants where she has treated them different ways. The bushiest is an older plant that was bent over like a horseshoe and the new side growth was used for clones, but there's plenty left and the overall plant shape really maximizes light to all of it. I really like that style, letting the main stem grow to about 12-14 inches and then pinching it and training it bent over.

http://boards.cannabis.com/indoor-gr...-log-p-11.html

Go down the page on this link and there's pics of how I start them out.