I'm study english, but what I learned was it: Near is anything or anyone that is around of you or something (ex: the bakery is near of us, it is in the same street that us) . Beside is anything or anyone that is on your side (ex: That woman is beside of me, she is touch in my arm).

I speak portugues, then can it have some mistakes.

Near means not far away in distance or space,but beside...is more like 'next to', Ahmed's example explains about that

as an example 

in a bus station if u are sitting on a bench u and a woman so she is sitting beside you and if there is a man standing somehow distant from you so he is near u

hope u got it :)