Varmint Al does have lots of good information on his site. Also keep up with the posts at
Sign up there and feel free to ask any question. You will get more information than you asked for.
But, we have some good conversation in our varmint section too so don't count us out.
You asked about the best calls. Well that runs from Haydels and other quality makers mouth calls of rabbits, rodent squeeks, and coyote howler.
Then on the electronic side the big leader is the new FoxPro FX-3, lightweight handheld with two internal speakers and a long distance remote control, 32 sounds (your pick and its reprogramable) for just under $500.00. A good Christmas present to yourself.
You are right on with your caliber choice. The 223 Rem is great and if your shooting distances will be further than 200 to 250 yds you might want to use a 22-250 Rem. But you will find that the 223 will reach out and touch them with good results. For quiet night time hunting I use a 22 Hornet and I am thinking about making it a "K-Hornet" for a little more case capacity and a touch more noise.
Get out there and knock them down. It seems you know how it's done