Season 5 Jungle has seen a lot of change from its past season jungles, and most if not all champs tend to start with smiting a large monster that gives them a buff for clearing jungles. Gromp (Blue Side Frog) gives you the ability to deal poison damage to your attackers, and Krugs (Red Side Rocks) gives you the ability to stun per 6 attacks.
Now, smiting Red and Blue buff does not give any sort of clearing buff or whatsoever. Instead, it gives you back a small amount of HP or MP back (HP for Red, MP for Blue). This is also true for Murk Wolves (Wolves) which gives you a ward in your Blue side jungle that chases enemy champions and Crimson Raptors (Chickens) which gives you true sight around you for a duration of time.
Why do people usually smite chickens instead of Red Buff you might ask, this would give you a safer clear (not necessarily better). However, the difference here is that at the end of your clear, you would want to gank a lane to pressure the lane. In this case, the true sight is immensly powerful as it gives you the power to detect Stealth Wards. If you happen to find any, removing them would force them to place another ward there (-75 gold for the enemy) or lose the precious vision there which often result in a devastating gank from mid or jungle.
However, this is still situational as if the enemy team jungle is shaco or nunu, you would want to smite the wolf in order to gain the ward in your side of jungle in order to prevent counter-jungling. Or you can also grab your clearing buff (either krug or gromp) then get the Red and the Blue buff in order to prevent the enemy jungler from taking any of those.
Also, do remember to take the small river scuttler (crab) in the river - they essentially give you free vision in the river, which will allow better control over dragon / baron.