Hi, Jen, and Welcome to the forum! Oscars are great fish. Here's a little thread from our FAQ's you might find useful:
http://oscarsfishtank.com/discuss/index ... pic=2846.0You might also look through the other FAQ topics to answer some of your other questions. I'd also suggest just looking thru the Oscar section of the forum for more info. No foolproof way to sex them without "venting" them. Here's a thread on that subject:
http://oscarsfishtank.com/discuss/index ... ic=22923.0The thing to remember about algae is that it needs two things to thrive -- nutrients and light. The nutrients part can be handled by filtration, water changes, gravel vacuuming, and feeding discipline. Best rule is to feed no more than they'll eat withing 2-4 minutes. Any excess is just going to decay, providing nutrients for bacteria and algae. As to the light part of the equation, just keep an eye on how much light is hitting the tank, from where, and for how long. Find ways to control it. Many of us use timers to control our aquarium lights. Check your room lighting, windows, etc, for other sources. To get it under control quickly, you might try just keeping the aquarium dark for a week or so till it clears up, then go to a more reasonable schedule. Good luck! Keep us posted!