1) Me, personally: I wouldn't ask for a raise (and this might be me just being pedantic) but I'd ask IF the role change has a scheduled raise and what is to be expected. I'd use this answer to help me make a decision. I'd (me, personally) would assume the role would have a minor raise and future raises based on my performance in that new job. I'd try to secure a 15-20 percent increase in pay for moving to a manager role - which, btw, is hard. Moving into a manager role means learning a new job - this isn't (or shouldn't be) your other job with a couple new responsibilities. This is an entirely new job that isn't your old job... sure, you can help people when they ask but that is entirely different than hiring/firing, writing people up, or trying to determine what sort of a raise somebody deserves.
2) Be humble. Find a mentor. Read a lot. Be humble. Be humble, be humble. I believe that power exposes more than it corrupts but it can also corrupt. Work from goals. Give clear expectations. Also, you may not like this role. I've hired a lot of developers leaving their company because they were great developers that were put into management roles and learned to hate it. Good luck! Me, I love it. (to each their own)
3) Learn. Read. Read. Learn. Read... and remember: In theory practice always works, in practice theory doesn't - You are now dealing with PEOPLE not COMPUTERS. People are emotional beings and often unknowingly irrational. HOW you say something is much more important than WHAT you say.
Lastly - learn to manage UP as much as you learn to manage DOWN.
Best of luck!