Things you should know
If you see a sequence of limestone on top of shale on top of sandstone, this means there has been a transgression of a shallow (epeiric) sea.
If you see the opposite sequence, then there has been a regression.
Terms you need to know:  epeiric sea, Pangea, Rodinia, orogen, orogeny, craton, hominids (human ancestors), benthic and planktonic organisms (and how they are useful), index fossil, stromatolite, banded iron formation, pillow basalt, komatiite (the previous four are rocks - the first a layered rock created by single-celled organisms, the second a layered rock that indicates fluctuating oxygen conditions, the third a volcanic rock that solidified under water, and the fourth a volcanic rock that requires an Earth with a hotter interior than we have today).
Other terms, granitoid/greenstone rocks (characterisitic of Archean), Wilson cycles (the opening and closing of oceans as supercontinents break apart and reassemble)
Principles of relative dating: original horizontality, lateral continuity, cross-cutting relationships, superposition, inclusions, fossil succession
Be able to recognize each of the followign types of unconformities: angular unconformity, nonconformity, disconformity

We've covered big chunks of time:
Precambrian (Hadean plus Archean plus Proterozoic - all time before about 540 million years ago).
Hadean Eon - almost no rock record, large impacts on moon, Mars, Mercury
Archean Eon - granitoid/greenstone belts - earliest single celled fossils positively identified
Proterozoic Eon - major geologic event - assembly and breakup of supercontinent Rodinian, see abundant stromatolites, banded iron formation giving way to red beds, Ediacaran fauna - first clear evidence for modern style plate tectonics - first multicellular fossils
Paleozoic Era - the big geologic event is assembly of supercontinent Pangea from pieces left over by breakup of Rodinia - development of almost all major phyla in Cambrian explosion.  Archeocyathids only in Cambrian, Trilobites only in Paleozoic, Rugose and Tabulate corals only in Paleozoic, Paleozoic ends with largest mass extinction (Great Permian extinction).
Mesozoic Era - midway through get hexacorals, towards end get angiosperms (flowering plants and deciduous trees) - only Era containing dinosaurs.  First birds and mammals - big geologic even - breakup of Pangea and formation of Atlantic Ocean. Mesozoic ends with 2nd largest mass extinction (K-T extinction).
Cenozoic Era - we're in it - mammals become big and dominate -pleistocene ice ages at end of Cenozoic (ended about 10,000 years ago), big geologic event is Alpine-Himalyan orogeny