Hi Darren,
Welcome to the forum....
N.guentheri is probably the best species you could have chosen when starting with annual killifish.
You should have a bag/container with peat laden with the eggs.
There should be a label or note with date collected and date expected on it.
When you get your eggs if they need storing until the correct date then do so in a padded envelope in a warm place.
On the expected hatching date take a small margarine tub and fill it to about 60mm with cool tank water and float it in an aquarium the fry will hatch almost immediately (if they are ready)I like to remove these from the peaty tub by means of a pipette and place into a new identical clean tub ready for feeding.
Add just a few grains of Cooking Salt at this stage to ward against velvet.
You will need, brineshrimp eggs to hatch and microworm cultures at the ready for feeding long before this stage.
The fry of Guentheri are large enough to accept bbs and microworms as their first food.
Waterchange in the tub daily removing all uneaten food with a pipette or a syringe with a piece of airline attached.
and replenish with fresh aged water.
After 3-4 days re-dry the peat to it's original consistency (damp as rolling tobacco) and store for another fortnight, you may be surprised to find that you will have more fry from the second wetting.
As they grow move them to larger quarters always keeping their vessel clean. After BBS and microworm they will accept Grindalworm and sifted Daphnia.
Regards
C
