Namaskar

Please, could someone direct me to some resources on Karma Yoga? That is books, on-line articles etc. I am specifically interested in the aspect of the seemingly trivial day-to-day activities of Man, like work, household tasks, physical exercise etc. I have a hard time in some cases understanding where the dividing line goes between when the actions are egoistic driven and when they become an offering to the Lord. Example: i have a choice to leave work at normal hours and go home performing Puja, meditate, reading the Gita etc., but i can also work overtime because i need the money that month to buy a new car. I will work my normal hours as an offering to the Lord, and i can work overtime as an offering to the Lord, but the latter will initially be egoistic driven, its basis will be of the lower personality

Shanti