There will always be more answers that might clear your doubts, but for the time being,

Try looking at this answer and the ensuing discussion, about the caste system and the influences of British rule on it

Also, this answer

Helps in understanding the development of varna and caste, the dynamics, social mobility and power structures among other things

And finally this answer sums up the previous two and gets into discussion about a relatively ambiguous caste and it's history