Which ever way you choose, it is important to buy the best tools and materials you can afford. This will save you a heep of money in the long run- not to mention better looking flies (believe it!). Personally, I would start out just buying what you need to tie with. Assuming your tying for Trout, the patterns I would recommend beginning with are:

1) 'Buggers- Olive, Black, Brown and Peacock
2) Hare's Ear Nymph
3) Pheasant Tail Nymph (Troth)
4) Adams
5) Elk Hair Caddis

The above patterns are generally the first ones that are taught in most tying classes. Some of the most productive patterns to boot.

If you choose the kit route, have a fly shop put one together for you. Most are willing to give a discount when you go this route. You might pay a little more, but it is worth it. I wouldn't think about buying one off the shelf. The quality of materials and tools are really not up to par. (I'll keep stressing this....)

And this is just the beginning...

Here are a few of my patterns: Midge X Caddis Carey Bugger GRHE Filoplume Prince Steelie Flies: Top Row

Downriggin'
(Funny moniker for a fly fisherman huh?)