Another fan of Charlie's book here (assuming you're talking about trout flies). It is very well laid out, and Charlie obsesses over details that other books often blaze through. This really helps a beginner get a good grasp of techniques, and his book has excellent and detailed photos that help explain techniques. And I've been tying for 30 + years and found a lot of very useful info there too.
In addition to doing a very thorough job covering tools and materials, he covers 17 specific patterns (and includes several variations for each). These patterns are great flies in their own right, but more important teach you a variety of techniques used on other patterns not included in the book. The patterns are a logical progression and go from very simple to more difficult. He also does a very good job of demonstrating and correcting pit falls you may run into and does a very good job covering proportions on different types of flies.
And you can pace yourself (and your wallet) a bit by buying materials for one or two patterns at a time.
Here's a listing of the contents:
1 How to use this book
3 Hooks and Thread
4 Attachment Techniques
7 Black Beauty
9 Gold Ribbed Hare's Ear
10 Pheasant Tail Nymph
12 Bead Head Prince Nymph
13 Copper John
14 Woolly Bugger
15 Hair Selection
16 Elk Hair Caddis and X Caddis
19 Rusty Spinner
20 Parachute Blue Wing Olive
21 X Comparadun and Sparkle dun
22 Royal Wulff
24 Goddard Caddis
After you work your way through the patterns, you'll have a very good grasp of different techniques. With the wealth of information on the web, including the zillions of step by step patterns out there, it becomes very easy to google a pattern like a Thorax dun (not included in the book) and follow the steps to tie it without the need for any additional hand holding, or pick up a book like David Hughes "Trout Flies" that is geared towards intermediate (rather than beginning) tyers, but covers a ton of different styles of flies including many different styles of wet flies, terrestrials and streamers not covered in Charlies book. Many of the specific patterns you'll want for PA just differ in hook size and color, so it's a simple matter of applying the same techniques. For example if you can tie a comparadun, you can tie a Sulphur, Hendrickson and any other Comparaduns, and if you can tie a BWO Parachute, you can tie other parachutes by simply varying color of hackle and dubbing. And learning the style of tying an Adams with the ability to split and tie divided wings (covered in the Wulff) will let you tie all the Catskill style flies.
If you want to get a feel for some of Charlies instructions, take a look at some of the step by step patterns he covers on his website www.copperfly.net
and click on dry flies, nymphs or wet flies. Just be aware that the step by steps on his website assume some experience and familiarity with tying. The book is more detailed and helpful for beginners and doesn't assume any tying experience. But after working through his book, you'll be able to tackle all kinds of stuff on his website and many others out there, and in many cases just a pic of the fly and a list of the ingredients will be all you need.
Good luck-- and don't hesitate to ask questions here as you get into it. Also, as the fishing season starts to wind down as winter approaches, be sure to look into local fly tying classes offered through shops or groups like local TU chapters and FFF affiliated clubs.