Hadeeth on Encouragement to Read

Perhaps the hadeeth referred to in the question is that which
was narrated by ‘Uthman ibn ‘Affan (may Allah be pleased with him), and says
that the Prophet (peace and blessings of Allah be upon him) said: “The best
of you is the one who learns the Quran and teaches it.” Narrated by
al-Bukhari (5027). 

There is a great deal of encouragement to learn to read the
Quran, both in the Quran and the Sunnah. There is also encouragement to
learn how to read. The Holy Quran is the only book that the Muslims read at
the beginning of Islam, so learning to read and write started with learning
the Holy Quran. Indeed the command to learn to read came with the first word
of the Revelation that came to the Messenger of Allah (peace and blessings
of Allah be upon him), when Allah said (interpretation of the meaning):  

“Read! In the Name of your Lord Who has created (all that
exists).

He has created man from a clot (a piece of thick coagulated
blood).

Read! And your Lord is the Most Generous.

Who has taught (the writing) by the pen.

He has taught man that which he knew not.”

[al-‘Alaq 96:1-5]

Knowledge spread and ignorance decreased as the result of
learning to read and write the Quran and understand its meanings. 

But if what is meant is another hadeeth in which it says that
Allah loves those who learn to read in general, then we could not find this
wording in any of the books of Sunnah.

And Allah knows best.