For a general reference, here [0] (PDF) is a somewhat detailed description (that is, it actually discusses how this particular implementation solves the problems that arise before it) of an out-of-order implementation for a simplistic RISC ISA. Suffice to say, it doesn't really have all that much in common with the classical 5-stage RISC pipeline.

[0] https://user.eng.umd.edu/~blj/risc/RiSC-oo.1.pdf