Feel free to ask questions here as they come up. Materials can be pretty confusing, and good quality dry fly hackle can be very expensive.
As far as hooks go, you may want to consider using less expensive hooks-- at least to start for your first tying efforts. Hook and Hackle Hook & Hackle Fly Fishing Tackle, Fly Fishing Supplies, Fly Tying Supplies and Fly Rod Building Supplies
sells 25 packs of their house brand dry fly hooks for 2.90 per 25 pack. They're pretty decent.
As far as hackle goes, you'd want dry fly quality, genetic hackle. There are many choices out there, with Whiting being generally recognized as the best quality, but also pretty expensive. There are also many alternatives in addition to Whiting that might be worth considering, depending on what you're tying, and on your budget. In addition to choices in brand, dry fly hackle comes in "grades" and also in your choice of capes or saddles. In addition to all that of course, it comes in many different colors.
Here's sort of a breakdown in terms of how it works:
Difference between dry fly quality and other types of hackle:
When you bend the stem of a dry fly feather the barbs will stick out straight, as opposed to clumping together and curving on "wet fly" hackle like hen necks or woolly bugger feathers. The "size" of dry fly hackle refers to the length of the barbs, not the overall length of the feather. Most dry flies will use hackle that has barbs about 1.5x the length of the hook gap (between shank and point). The smaller the hook, generally the more expensive the hackle-- finding a neck or saddle that will tie flies into the 20's will generally be more expensive than finding necks or saddles that will tie sizes 18 and up.
Difference between capes and saddles- capes (also called necks) have feathers shorter in overall length than feathers from saddles. But capes will generally have a wider range of sizes, so that you can tie flies that range in size from 12 to 18 or 12-20 or smaller, depending on the "grade". Saddles are a bit easier to work with, and have thinner more flexible stems, but they typically are strongest in only two or three sizes. Whiting saddles for example tend to have most of their feathers in sizes 14 and 16, with a few 12's and 18's. Saddles from other brands generally are stronger in sizes 10-12 or 12-14 with some feathers on either side of their main size range. Another product worth mentioning is Whiting 100's. These are packs of Whiting saddle feathers that are sold in one color and one size. The pack will have 12 or so feathers, and will be enough to tie 100 flies in that one size and color, and will go for about 18 bucks a pop.
Difference between grades - Whiting grades their necks and saddles in Gold, Silver and Bronze. Other brands grade their necks 1, 2 and 3, and sometimes "Pro". The higher the grade the more expensive. Higher grades will tie more flies (more and longer feathers) and in the case of capes, will generally tie down into smaller sizes. Most capes in grade 3 or Pro grades will tie down to 18, Bronze whitings down to 20, and the highest grades of necks (and most expensive) tying down into sizes 26, 28 and smaller. Grades for saddles generally reflect the length of the feathers, rather than the sizes they will tie. A higher grade saddle, because of the length of the feathers, will tie more flies. It is not uncommon to be able to get 6 or 7 flies out of one Whiting silver saddle feather.
Color- there is a wide range of colors available both natural and dyed. For someone just starting out it might be a good idea to start out with brown and grizzly. The feathers can be used separately or mixed together like on an Adams. These two colors will let you tie a range of patterns like Adams, Elk Hair Caddis. After a bit, the next colors to add might be a medium dun medium gray color) and a cream or light ginger. These colors can be also mixed or used individually to cover a pretty wide range of patterns.
So what should you get?
If you're just starting out, and on a tight budget, remember that tying larger 12-16 is going to be easier and less expensive than tying smaller flies in 18 and 20.
For about 30 bucks each you might want to consider buying capes that will tie a size range of 12-18:
Herbert Miner "Pro" cape (these are now owned by Whiting and are sold under a green label). These can be found in many stores.
Conranch grade 3 cape. Denny Conrad and his daughter Liz are independent breeders with good quality feathers from 12-18 you can see their stuff at Conranch Fly Tying Hackle
or Collins grade 3 cape for sizes 12-18 which includes a free dry fly quality saddle that typically are strongest in sizes 12 and 14. Charlie Collins doesn't have a website but you can order directly from him by calling 607-734-1765
Both Denny and Charlie will be happy to answer your questions and make suggestions to make sure you get what you want for whatever you're tying, and the quality is very good and the price is great.
If you want to tie smaller stuff, some of the capes you get may have some size 20 feathers. But if you need more you can order a pack of size 20 or 22 Whiting 100's in grizzly. That will cover a lot of bases without spending a ton on a higher grade neck.
Another altenative is to consider tying some dry flies that don't use dry fly hackle. Sparkle duns and X Caddis use deer hair for flotation (sold as comparahair or coastal deer hair). By varying the size of the hook and dubbing color you can imitate virtually any caddis and mayfly hatch 10-18. In contrast to hackle, a 2" x 2" patch of coastal deer hair will set you back 3 bucks and is enough to tie 100 flies. For smaller flies size 20 -26 tie them with CDC feathers. CDC = Cul de Canard feathers, a pack will set you back 3 bucks or so and will tie about 2 dozen small flies. These are super inexpensive, easy to tie once you get the hang of it, and are VERY effective. There are vids out there if you want to google them to see how to tie them.
Hope this helps a bit. Ask questions as they come up.