Alright, back in the office now. K, we're talking new born pullets so there is not a ton that needs to be done, but there are some items that are absolutely essential.
Lets start with water. I will remind any producer of any kind regardless of what they're looking for in raising birds that water is the most important thing. Keep that water clean enough for your own children to drink it. I cant stress this enough. Change it daily if practical.
-Additives for your birds now should include a product called Red Cell. Not "Red Syrup" of "Pro Red". Those are common knock offs that cost the same. You want "Red Cell". The instructions will be on the bottle and you can use their measurement guide to know how much to add per gallon of water. (GET THIS IN THEIR WATER ASAP).
I can expand on this portion if need be for you but for now lets move on.
Feed:
You're undoubtedly housing the pullets in the same pen as your hens still and that's ok if you'd like to keep it that way. Just know that you will not be able to easily separate the birds when it comes to feed. I encourage you to eventually separate the pullets from the rest of the flock in the very near future. With that said, you're looking for a feed product that is:
A. Easily available
B. Fairly cheap
C. High in protein (20%-28% for birds the size of yours now)
You want a product that offers a variety of protein levels so you can remain consistent with a brand. I'm not a feed rep, nor do I play one on the Web. Depending on your area feedstores, brands like Dumor & Purina are a good fit and address the issue I stated above. Dumor can be found at Tractor Supply by the way.
General health issues:
Don't you go and stick a needle in any of those pullets. That's absurd first and foremost. Birds this size may experience very little health issues to be honest. Your goal is to keep them fed and growing. Concerns about health at this point have more to do with your pen condition than anything. Its true that Coccidiosis can occur in youthful pullets. You'll notice their stool being exceptionally loose and the birds will appear flat out puny. Coccidia is a parasitical disease that is curable, but left untreated can result in death. It spreads too. My advice? If you see one that looks like its even thinking about getting sick, "discard" that pullet.
To treat a case of coccidiosis you'll be looking for a product called Corid 9.6%. Its a water supplement and you should use it in a separate water that is not mixed with Red Cell. You'll need to separate the infected pullets, provide feed as normal, and offer the Corid water for a period of 5-7 days. This has worked in early stages of pullet production, however, the more severe cases are often too far gone.
Note: Some producer have told me that they avoid the risk of infection by feeding medicated starter specifically from the beginning. I advise you not to do so. It cost more, and you're putting stress on the immune system for no reason. Once the birds mature, and immunity is built up and the risk of this fades over time. Adult bird cases of coccidiosis are fairly rare.
I can expand on this further if need be.
Lastly, to address health concerns, the pen temp. I know its getting hotter here in Texas now, but I don't know where you live so I'll say this; for the next few weeks keep them as warm as practical. 90 degrees in fact or as close as you can get it. "That's damn hard to do 07, and that'll burn them all up!" you might say. You'd think that, but you'd be wrong.
Think of the method of swaddling an infant. Why do we do that? Because its comforting to the child because it simulates them being in the womb, which up until birth, was an awesome place to be. Same goes for pullets. They just got out of an egg. I'm not saying this is extremely vital, but I'm suggesting that you make an attempt to keep them as warm as you can for now. You will be cooling them down soon so whats a few weeks of running heat lamps really?
I'd be happy to entertain any other questions as always and hope this gives you some idea. I am passionate about poultry production as much as I am about college football and love talking about it just as much so any of y'all, ask away.