Question Summary:
Question regarding Durood

Question Detail:

Is the following durood valid for recitation:
Allahumma salli ala sayidina mohammadin wa ala sayidina mohammadin wa barik wa salim.
 
Furthermore, is there a more recommended short durood.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
The Durood mentioned in reference is authentic.
Durood basically means sending salutations upon Rasulullah (Sallallāhu Alayhi Wasallam). Any form of salutation is referred to as Durood.[1] The shortest form of Durood is صلي الله عليه وسلم. However, the best form of Durood (duaa and salutations) upon Rasulullah (Sallallahu Alayhi Wasallam) are those that are recommended by Rasulullah (Sallallahu Alayhi Wasallam) himself. There are many authentic Durood (Salaat and Salaam upon Rasulullah sallallāhu alayhi wasallam), mentioned in the Ahaadith. Hadhrat Sheikh Zakariyya rahimahullāh has compiled 40 Durood from Ahaadith, which may be found at the link given below. http://veiledgems.files.wordpress.com/2013/03/40_durood_with_meaning__transliteration.pdf
And Allah Ta’āla Knows Best
Asim Patel
Student Darul Iftaa
Venda, South Africa
Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net