Peter Henshaw wrote this buyers guide about the Indian made Royal Enfield Bullet. Definitely worth to buy it if a Bullet is the first bike you gonna buy. The book if giving mostly general advice, rather than specific on the Bullet.
As an example, you can find the advice to look for rounded bolt heads or twisted cables. But that counts for all bikes.
The official price is £ 12,99 (Veloce) but discounted versions can be found all around.