I'm a developer who hated sales and was pushed into it because all the other members of the team were developers who hated it more than I did.

Some great tactical recommendations have been made here, but the author who got me to re-think what sales was and to see it as honourable and helpful was Zig Ziggler.

His books are old-school, but reading them will make you enjoy selling.

I'd recommend "Secrets of Closing the Sale" to start, but all of his early work is good. His later books get a bit self-helpy.