Im just a 100 miles shy of the big 50k point. This is the first car Ive actually done a bit of work on, and is my learning car. I was wondering what major things might need a check up or to be replaced at 50k?

check your brake pads
suck the fluid out of the power steering reservoir and put new fluid in
flush the engine coolant
replace the transmission fluid and filter (if it's an auto)
change oil and filter

of course, 60,000 miles is really the interval this stuff should be done at.

what happens at 60k?

60k is normally when you do the tune up not 50k.