Hey Sheila
I use card blanks too - I get them via e-bay from a paper manufacturer who's catering for card makers as well as companies. They come prefolded and with envelopes. I have started to get card with a weight of 300gsm as I find if I add lots of embellishments, the finished card still stand upright beautifully. I use any and all the regular shapes available, but love the square and long thin (DL) variety best I think.
I also use the same supplier for sheets of plain white card onto which I print embellishments from the digi-kits.
I use sharp scissors (a large and small pair) and a very sharpe bladed knife for cutting (don't forget extra blades) - but you
must have a cutting mat to protect your work surface

I have some punches for regular sizes plain and scalloped circles, squares etc, otherwise I snip out by hand too - it can be quite theraputic with some music on! Honestly!
Again like Monique, I use glue dots and double-sided tape in various widths (great for sticking ribbon onto your card). I also use a normal glue stick and a glue pen for accuracy at the very edges of my card when sticking paper onto my card stock. I like having a stock of stick foam pads too to add a little dimension to images too.
If you are just starting to see if you you like making your own, just try your local stores, but when you are convinced that homemade cards are the best (which you will!!) then do take a browse on e-bay as there are lots (and LOTS) of stores with good deals on paper, glue, tape etc..
One more thing I'd recommend - a nail file! I use mine to gently sand any rough edges on anything I cut out.
I warn to, once you start, you'll be contantly adding to your kit - its addicitve! Just think: ink pads, chalk, brads, ribbon..... lots of pretty things to play with :thumbup:
Enjoy!