Help please "First bow quetions"

[Clay Chapman]

I have started my first bow, I am making a relex/ deflects longbow, with action boo core lams, zebra wood outers, purple heart inners, between clear glass. I have the riser glued up and its cut out, I got a good taper on it as I was told this was important. What I need to know is I'm betting ready to put it in the jig and was wanting to know

1. Is there _anything_!!! helpful to know when gluing up
2. Can somebody explain tillering in detail.
3. And the best way to avoid limb twist, or how to correct it.

Any info would be greatly appreciated. Thanks