One of the major sutras is the Mahaparinirvana Sutra. Here is an online version with comments & studies by Dr. Tony Page.

http://www.nirvanasutra.org.uk/

An important title that was recently translated is the Mahayanasutralamkara.

Here is a review by Georg Feuerstein:

http://www.yrec.info/reviews-65.html

Mahaparinirvana Sutra
On Boundless Love [Maitri]

[Rendering based on Yamamoto's translation, pp. 378-80.]

Good man! All the roots of goodness of sravakas, pratyekabuddhas,
Bodhisattvas, and Tathagatas are grounded in love.

Good man! When the Bodhisattva-Mahasattva exercises his loving
heart, he gains countless roots of goodness. He gains all types of
power, quality, meditation, or knowledge needed.

Good man! All such are grounded in love.

Good man! Because of this, love is true, not false. If anyone
asks about the root of all branches of goodness, say that it is
love. Because of this, it is true, not false.

Good man! One who acts nobly is thinking truth. This true
thinking is love. Love is Tathagata. Love is Mahayana. Mahayana
is love. Love is Tathagata.

Good man! Love is the bodhi path. The bodhi path is Tathagata.
Tathagata is love.

Good man! Love is Maha Brahma. Maha Brahma is love. Love is
Tathagata.

Good man! Love acts as parent to all beings. The parent is love.
Love is Tathagata.

Good man! Love is the nature of the inconceivable world of all
Buddhas. The nature of the inconceivable world of all Buddhas is
love. Know that love is Tathagata.

Good man! Love is the Buddha Nature of all beings. Such a Buddha
Nature is heavily veiled by illusion. That is why all beings are
blind. The Buddha Nature is love. Love is Tathagata.

Good man! Love is the great firmament. The great firmament is
love. Love is Tathagata.

Good man! Love is space. Space is love. Love is Tathagata.

Good man! Love is eternal. Eternal is Dharma. Dharma is the
Sagha. Sagha is love. Love is Tathagata.

Good man! Love is self. Self is Dharma. Dharma is Sagha.
Sagha is love. Love is Tathagata.

Good man! Love is amrita. Amrita is love. Love is Buddha Nature.
Buddha Nature is Dharma. Dharma is Sagha. Sagha is love. Love
is Tathagata.

Good man! Love is the peerless path of all Bodhisattvas. The path
is love. Love is Tathagata.

Good man! Love is the limitless universe of the Infinite Buddha,
the World Honored One. The limitless universe is love. Know that
love is the Tathagata.

By the way, for those who may not know, the middle -th- in Tathagata is not pronounced as the dipthong -th- like in the word "third". Rather, the T and H are separated, as "tat ha ga ta".

According to a Sanskrit-knowing friend Tathagata is pronounced - Tuh tahg uh tuh - with emphasis on the bolded syllable.

Does "tahg" rhyme with "dog"?

Pretty close - imagine you are from Boston, where they have Dahgs, not Dohgs or Dogs.