Hi S.G.,
I'm 46 and I've worn makeup everyday (well, almost every day) for 30 years. I agree with Poreoily about visiting a cosmetics counter. And Clinique is great for us over-forty types. But try to find a counter person who looks close to our age because makeup wears differently as we get older. One thing I'm sure of is that you have to wear less as you get older. You should probably cover your whole face, but spread very little over large areas. I run my fingertips under water when spreading my base makeup in order to thin it out (this takes less skill than using a makeup sponge). And though I used only powder shadows when I was younger, I now use only pencils. The oil in them seems to keep my skin from looking scaly. Avoid dark eyemakeup as it tends to look like dirt at our age. A lot of my friends use their blush as eyeshadow which offers a healthy glow, though you want to use very little. This looks best if you're using peachy shades, which I do. Choose a neutral eyeliner to keep the rest of the face from looking washed out. And put mascara on your bottom lashes first (I probably don't have to tell you why). And be sure to line your lips with a pencil to give it definition. This takes lots of practice, but it's well worth it. Just be sure to match your lip pencil to your lipstick, and keep the color soft (no harsh reds).
Good luck and have fun!