Anyways, I'm learning Digital right now and have a few questions.

So far, I know about the logic gates, the SL chips, boolean algebra, converting to hexadecimal, decimal, octal to binary (and reverse) and truth tables. The only thing I'm confused about is using combinations of logic gates. When I'm using a logic trainer and IC's I'm able to understand it through application. But I have no clue as to how to draw this stuff on paper. What steps do you take to build something using a combination of gates.

Lets take this for example; if ALL "gear" "flaps" and "speed" are "1" or hi the green light goes on, if any of these are lo or "0" then the buzzer goes off and a red light goes on. What steps should I take to build this kind of scenario. Do I first look at the truth tables, logic gates and then connect them. Whats a good way to combine logic gates together?

Secondly, I'm learned about HD and Octal conversions, how does this stuff apply to digital electronics. Can you give me a few examples of how this would apply?

Thanks alot for any responses!