^^ good advice
Personally, if I was starting a server, I would actually try & google seeds that give maps that have most of the main biomes within xxxx blocks from 0,0 (it depends if you are setting a world border or not)
[I would also try & find a seed that had an Island at/near 0,0 for the spawn hub to replace it & let players sail to the biomes around it]
If you have a world border then this way players can get a majority of the resources without having to explore too far..
Sometimes you MAY get a seed in AMIDST that doen't have a particular biome (it's rare but can happen) within your world border, meaning that players won't be able to get a certain resource (eg I had a seed that had no Jungle biome within a 10,000 block (-5000 to +5000) world border - yeah I know it was a small world)