Sunnah Way Of Cutting Nails

Before Jumu'ah (Friday)
Abu Hurayrah (May Peace & Blessings be upon him) has related that, 'The Messenger of Allah (May Allah bless him and grant him peace) before going to Friday prayer would clip his nails and mustache.' 

Every fifteenth day
The Messenger of Allah (May Peace & Blessings be upon him) would get his nails pared every fifteen days. 

Do not exceed forty days
Anas (may Allah be pleased with him) relates that the Messenger of Allah (May Peace & Blessings be upon him) said that, 'Do not let forty days elapse without trimming the mustache and paring the nails.' 

Personal Suggestion:

We must follow this Sunnah and cut our nails as prescribed by our beloved Prophet (May Peace & Blessings be upon him). If we teach others the Sunnah of Prophet Muhammad (May Peace & Blessings be upon him) and they follow it then we will gain the reward for this till they follow it by the grace of Allah (s.w.t). Rest Allah knows best.