As mentioned by Lord Gampopa in the Jewel Ornament of Liberation, the benefits of Generosity or Dana Paramita are as such:
Engaging in the Middle Way says:
These beings desire happiness,
And all human beings who are without wealth have no happiness.
Knowing that wealth comes from generosity,
Buddha spoke first of the practice of generosity
With generosity, one can gather trainees and establish them in the precious Dharma. It is said:
By the practice of generosity, one an fully mature sentient beings who are suffering.
The Bodhisattva Basket says:
For those who practice generosity, achievement of enlightenment is not difficult
The Cloud of Noble Jewels Sutra says:
Generosity is the enlightenment of the bodhisattva
The Bodhisattva Bhumis says:
One will become strong by giving food
One will achieve a good complexion by giving clothes
One will become stable by giving conveyances
One will have good eyesight by giving lamps
The Precious Jewel Garland says:
By giving fearlessness to those who are in fear,
One will be unassailable by all the maras
And will become supremely powerful
The Precious Jewel Garland says:
Giving Dharma teachings to those who listen
Causes obscurations to be dispelled
And one will accompany all the Buddhas
One will quickly achieve all that one desires
There are three types of giving: Gift of Wealth, Gift of Fearlessness and Gift of Dharma. The gift of Dharma is the most beneficial ultimately, as it allows the sentient being to escape the unbearable sufferings of Samsara and achieve everlasting happiness. The gift of Fearlessness is protection from animals, rivers, robbers etc. Giving of wealth includes money and material items. Except for bodhisattvas who actualized the equality of self and others, a practitioner should not give up parts of their body.
