can anyone give me some good references on how to obtain the relativistic equation of particles with arbitrary spin?
Since you're specifically asking for references, the only reference on this subject that I'm aware of is an old artlcle by Wu-ki Tung:
"Relativistic Wave Equations and Field Theory for Arbitrary Spin" Phys Rev Vol 156 #5 pp1385-1398 Apr 1967
It may be available online somewhere. It talks about the extra restrictions you might want to impose in order to obtain reasonable field equations and talks a little about what's special about the cases of spin 0, 1/2 and 1.