Hello and welcome. A few thoughts on your post:
1) You will need some sort of predator to control the crappie and bluegill in your pond. Five years of unchecked reproduction will likely mean that there are lots of small crappie and bluegill present. However, 100 total fish for a 5 acre pond isn't a lot, so there is a chance that it hasn't become an issue yet. Largemouth bass are one of the few fish that can control bluegill in a pond but they can put a huge dent in a population of yellow perch as they're easier for them to eat so it may be difficult to establish them. Smallmouth bass would be a better option for yellow perch but can't control bluegill.
2) Five acres isn't usually considered to be large enough for crappie, but there are exceptions to the rule. Were any other fish in the pond than the bluegill and crappie before it was drained?
3) Stocking minnows is probably dependant on the current fish population. If you have lots of hungry crappie they probably won't last very long. If the fish population has remained low, they may be able to establish themselves. Fathead minnows will most likely end up being eaten no matter how well they initially do. Golden shiners have a better chance of becoming established long term.
There are lots of people more knowledgable than me here who will be able to provide more input and options for you, someone will be along soon!
