MOSFET selection for 5V LED Circuit
Let's go over the main specs of the MOSFET...

Drain-Source Voltage (Vdss)=60v.  You will be subjecting it to 5v, so you're good!  

Gate-Source Voltage (Vgss)=20v.  You're at 5v, so good.

Drain Current (Id)=300 mA continuous.  You are at 100 mA (20 mA for each of the 5 LED's).  Good!

Gate Threshold Voltage (Vgs(th))=1.0-2.5v.  You'll be driving the gate with either 0.0v or 5.0v, so here again you are good.

I ignored some of the more esoteric specs, which could come into play if you were driving an inductive load like a motor or relay, or needing to have fast switching or high-frequency switching.  But for turning some LEDs on or off, this MOSFET will be just fine.