Excessive fasting during the month of Shabaan is good.
(Saheeh Bukhari, Saheeh Muslim)

For the reason that during this month acts and deeds are elevated towards Allah.
(Nasai, Sanad Hassan)

Keeping fast on Mid-Sha’aban (15th of Sha’aban) is very good. However; if, due to any reason, unable to fast on 15th of Sha’aban, then in lieu of that should keep two fasts after Ramadan.
(Saheeh Muslim)

Not to keep fast after Mid-Sha’aban (15th).
(Abu Dawood, Tirmizi, Sanad Saheeh)

Not to keep fast on 30th of Sha’aban, in doubt that it was first of Ramadan.
(Abu Dawood, Tirmizi, Sanad Hassan)

In case it is cloudy on 29th of Sha’aban, and the moon is not sighted, then complete thirty days for the month of Sha’aban.
(Saheeh Bukhari, Saheeh Muslim)

Observe the Sha’aban moon with care and keenness, and then keep on counting the dates of Sha’aban for the arrival of Ramadan.
(Tirmizi, Sanad Saheeh)

As a welcome gesture for Ramadan not to keep a fast or two at the end of Sha’aban, save those fasts one is always keeping regularly, like fast of Monday or Thursday.
(Saheeh Bukhari, Saheeh Muslim)

Note: There are few narrated ahadees for establishing sacredness of the night of 15th Sha’aban. However, according to learned religious scholar, Ibn-e-Wajeeh, all these ahadees are un-Saheehated and uncertified. There is no Saheehated and established hadith for worshiping on the night of 15th, or any other during the month of Sha’aban. The narrated hadith in support of worshipping on the 15th night of Sha’aban is false and fabricated. Even going to graveyard is not established on this night. Except keeping of fasts during the month of Sha’aban, every thing else practiced in or attributed to this month is forged and fabricated.
(Miraat, Book: 3, Page: 238, 349)

Even the narration, that the names of all those to die next year, are handed over to the angel of death (Mulkul-Maut) in written form, is not correct.
(Miraat, Book: 4, Page: 267)