did not know that - might just delete this post then - assuming that know one really knows whats legal and whats not
Emulators are legal. Roms are, for the most part, illegal. If it's a rom of a copywritten software, it's illegal. For instance, you can't post a link to a website that hosts ROMs of Zelda games.
There are some websites that MAKE original roms, but those are pretty few and far between.
In general, probably just avoid roms altogether. Feel free to post links to emulators, as long as the websites don't have ROMs as well. Talking about ROMs is fine as well, as long as there is no discussion about how or where to find them.