"All the sublime teachings, so profound--to throw away one and then grab yet another will not bear even a single fruit. Persevere, therefore, in simply one." --Dudjom Rinpoche, "Nectar for the Hearts of Fortunate Disciples. Song No. 8"
There is no other book that is better on this topic. It is an amazing book containing crystal clear instructions on everything you need to know for Medicine Buddha practice. Not only that, Rinpoche explains the creation and completion stages in a way that is helpful for any yidam practice.
One should do nothing other than benefit sentient beings either directly or indirectly - Shantideva