The Higgs boson is just another particle that may or may not exist. It has couplings to the quarks, leptons (possibly neutrinos, but we don't know for sure) and the W and Z gauge bosons. To everything that it touches, it gives mass. I would suggest looking up "Higgs Mechanism" to get an understanding of that, both here and on the web. I don't know how much quantum mechanics you know, so I can't be more specific than that.
It also touches massless things, but indirectly. For example: a Higgs boson can decay to two photons. What it REALLY does is that it decays to a quark-antiquark pair (for example), and the quarks annihilate into two photons, but this happens so quickly that we only see it as a higgs ---> 2 photon event. In fact, if the Higgs exists and has the mass many people think it has, this is the best chance we have of seeing it (detectors at the LHC are set to look for two photons!).
That's obviously a bit oversimplistic, but I hope it helps getting you started!