Shaykh Bin Baz rahimahullah was asked:

 Are there any specific legislated affairs with which the Muslim greets Ramadhaan?

The Month of Ramadhaan is the best of the months of the year, because Allah-Subhaanahu- has specified it by making fasting obligatory in it, and by making it the fourth pillar from the pillars of Islam. He also legislated for the Muslim that he prays the nights of Ramadhaan, as the Prophet (sallallaahu alaihi wa sallam) said:

“Islaam is built upon five, The testification that none has the right to be worshipped in truth except Allah and that Muhammad is his Messenger, the establishment of the prayer, the giving of obligatory charity, fasting the month of Ramadhaan and performance of Hajj.” 1

And he (Sallallaahu alaihi wa sallam) said

“Whoever (establishes the month of Ramadaan –by fasting and performing all types of righteous action) with the belief (that it is legislated by Allaah), and hoping for reward, He (Allah) will forgive him for his previous sins.”2

I do not know of any prescribed thing for the receiving of Ramadhaan except that the Muslim receives it with happiness, being delighted and rejoicing, (and) that he thanks Allah for the coming of Ramadhaan and that He has given him success by making him from those who are alive and those who compete in righteous actions.

For indeed the coming of Ramadhaan is a tremendous blessing from Allah, (and) because of this the Messenger (sallallaahu alaihi wa sallam) use to give his companions the glad tidings of the upcoming Ramadhaan and clarified to them its virtues, and that which Allah has prepared a great reward for those who fast and stand (in voluntary prayer at night). Allah has legislated for the Muslim the greeting of this month with sincere repentance and that in preparation for his fasting and standing, he should have a sound intention and a genuine firm resolve (for fasting, praying and performing all types of righteous actions).

1 Bukhaari and Muslim

2 Bukhaari and Muslim

 Source: Majmoo Fatawa of Shaykh Bin Baz Volume 15 pgs 8-9