Coryadoras are very easy prolific egg layers, its as simple as own tank, 30% water change with cold water and then watch them lay eggs!
The cold water simulates spring time so they start a breeding frenzy, you can get hundreds off a single female but more than likely you will lose half of them as the water conditions need to be kept ideal at all times. Now because of the huge numbers you can get with these fish they are pretty cheap to buy and hard to sell so the next fish i'd recommend is the Rainbow Bosemani, they lay their eggs in clumps of java moss of a night, you can transfer the moss to another tank and replace it with more moss, if you repeat this several times a week you will have a nice big shoal of Beautiful fish in no time plus you can get alot more money for the excess!