10 years ago now (when did I get so old...) I started with one boy in a small tank hidden in a closet. No one should bash you for researching :D
As for tank dividers. Michaels sells the plastic mesh for .59c per sheet. I highly recommend it-- I just bought some today because some girls of mine decide their filter was a cool place to hang out.
Aquarium silicone is easy to find-- just look for tubes that say 100% silicone. Mine are "GE Premium Waterproof Silicone". They say they aren't for fishtanks, but that's a liability thing. As long as they are 100% silicone you are okay. Avoid anything that doesn't say 100% silicone, because they may have additions. I've found the GE brand at both Walmart & Lowe's. I let any new decor cure for at least 12 hours before I introduce it.
Beware, once you realize the power of silicone you will start silicone-ing random things together...PM me if you want any ideas.