Adding to investments monthly...?

[Eidal]

I'm interested in investing 1k and adding another 1k every month. I really have no idea where to begin, and I was hoping someone would have some advice or be able to point me in the correct direction.

Its my understanding that certain types of investments would be costly were I to add to them monthly (fees involved?), so if anyone could edify me on what I should be looking into I would be most appreciative.