There's a good reference book called fly fishing the grand river by Ian D. Martin. It's a good book for tiers as it gives you sizes for grand river bugs but in my opinion almost all Souther Ontario flies are within his suggested sizes and he gives you the sizes in mm not hook sizes which can be different from one hook company to the next. Fly colors should be very similar from one river to the next... On some rivers like the Saugeen, beaver, notty you may find flies that dont exist on the grand or other rivers but the basics flies are there in this book..
Also, dont just rely on the smaller flies. Flies like the hendrickson in size 14, Grey fox - size 10 and 12, isonychia size 10 and 12 and some hex and drake patterns from size 6 to 10 can catch a lot of big fish and can be very important hatches and flies to have in your box. Not to mention size 6 - 12 stoneflies, crickets, grasshoppers, and other terrestrial patterns.. Big flies catch big fish..sometimes.....
You can also find some decent hatch charts for specific rivers if you research it.
Here's a tip.. if you cant afford to buy hackle, there are some alternative materials and patterns that work equally as well as hackle and are much more cost effective and sold in smaller sizes. Deer and elk hair comparaduns are an example. I've been using a lot of dry fly patterns with CDC and with no hackle and they work great for me and my customers and are also easy to tie. Last year I was guiding a guy and he pulled out a CDC comparadun pattern that took multiple fish, actually 12 good browns in about an hour.. the only thing with CDC is you may want a few of each because once it gets water logged you'll need to put on a newer dry pattern. Usually they dont water log unless they're being munched on by fish which for me is a fair trade off.
If i have the time i'll try to post a picture or two of my CDC dries.. Right now i'm guiding a lot and tying like crazy but it's mostly nymphs i'm tying.. I think i've tied about a 100 czech style nymphs in the last 3 days because we've been hammering steelhead on them and losing way to many flies lately...
check this out for some examples of some CDC dry flies..
and
http://www.llbean.co...-cdc-comparadun
Have fun,