Answer: Removing spent flowers, or "deadheading", is usually a good idea as it helps the plant direct its energy toward growth rather than seed production. The specific place to cut depends on the perennial in question, so without knowing which ones you have it is impossible to tell you specifically. Winter preparation also varies depending on what you are growing. Luckily, perennials are generally not all that difficult to care for, so I'm sure you will get the hang of it quickly.
I think your best bet, if possible, would be to consult with some experienced local flower gardeners to see first-hand how some of these things are done. You might also wish to locate a few books on perennials and read up on the ones you are growing. Two possible choices to look for would be first as a thorough introduction to perennials "Perennials for Dummies" by Marcia Tatroe and the Editors of the National Gardening Association ISBN 0-7645-5030-6; and then as you gain experience the very detailed "Perennials for American Gardens" by Ruth Rogers Clausen and Nicolas H. Ekstrom ISBN 0-394-55740-9.
Enjoy your perennials!
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