Need some advice on getting my first smartphone!

Brand
Any brand will do.

Budget
Should be 500-1300 I hope. Haven't discussed the budget with my dad yet.

Specs
I will most probably use my phone to browse the web, read e-books and stuff like that. Don't think that I am much of an apps-guy.

» OS: For some reason, I feel like I would like to use Windows OS rather than Android. Android would still be fine.

» Camera: A decent one should be good.

» Battery life: A longer battery life is better.

Size
Medium sized I guess. Don't really like big sized ones.

Thanks in advanced.