You don't sound dumb at all! Every food--from yogurt, to beer, to pickles, to
apple cider vinegar, etc, etc--has different fermenting requirements, it's a really good question as to how to get it started. From my understanding, there are two options:
(1) You can just put the feed in a jar and cover it with water, and cover it with a papertowel or piece of cloth. Stir it at least once a day, and in about three days (at about room tempurature) you'll have fermented feed. And, you're right, when you see bubbles, you've got them fermented. You can use the extra water on top of the feed to "kick-start" the next batch.
(2) You can add some water from raw lacto-fermented veggies (pickles, sauerkraut, etc).
Bubbies Pickles, for instance, is raw lacto-fermented pickles. If the ingredients to the pickles or 'kraut has vinegar, they aren't lacto-fermented.
That
should get you started! Here's some more info on it:
This is the webpage that I based my method on:
http://www.yellowbirchhobbyfarm.com/fermenting-chicken-feed-the-easy-way/. They have great instructions! Instead of using left over feed to start the next batch, I just use the liguied
This person (
http://www.gardenbetty.com/2013/05/why-and-how-to-ferment-your-chicken-feed/) just strains out some everyday, and then adds more in, resulting in some more fermented than others. I don't trust this method as much, just because I don't really want to feed my ducks feed that may have been fermenting for 5 months...
This website has a lot of good tips, too:
http://www.backyardpoultrymag.com/10-fermenting-tips-reduce-chicken-feed-costs/.
One thing I forgot to mention (because I'm on a well and don't have to worry about it), is if you are on chlorinated tap water, any water that you add to your feed needs to be dechlorinated. To dechlorinate it, you just need to let it sit out in the open for 24 hours.
I hope that helps!