"those words" - (grammar question)

I have a million questions on Japanese

Narrowed it down to the most important one to me. Maybe its explained on a page I've missed - havent found it yet though! Typically I've been learning sentences, words and phrases...
yet I have a fairly limited understanding of "those words" eg: ni, na, ne, ga, wo, wa, o,

Can anyone show me the light?

thanks a bunch
Pablo

They are called "particle" (except "na" and "ne", also wo=o), and you can find a lot of information by googling with "Japanese particle" as key words.

You can get the basics of particles from the sites below:

Japanese grammar - Wikipedia
Japanese particles - Wikipedia

The major particles - Tae Kim's Japanese grammar guide
Verb-related particles - Tae Kim's Japanese grammar guide
Noun-related particles - Tae Kim's Japanese grammar guide