What people wore

Should one have the (mis) fortune of ending up in the seventeenth century, it is probable there would be far greater concerns whizzing about one's head than what one was wearing.

Food would be an issue. Porridge, more porridge, cold, dry porridge cut into slabs. Yummy. (More on the issue of food can be found in what people ate. Click here if you think food is more interesting than clothes)
Hygiene would be a major, major problem. Start by considering the fact that there was no toilet paper, no showers, no sinks, and in most of the towns and cities of the time the availability of clean water was scarce. Go on to think about toothbrushes and deodorants, imagine just how much people would smell, going about in more or less the same clothes for weeks and months. 
Health ... let's hope you don't need dental work, okay? An abscess in your mouth could prove fatal. Any major wound could become gangrenous, people died of measles, smallpox, the plague, strep throat - you name it. A word of advice would be to stay well away from towns and cities - chances are you'd have succumbed to an unsavoury disease within some months otherwise. 
Sharing beds with people not your chosen partner would, for most of us, be an uncomfortable experience. Even more so when said beds would be infested with lice, fleas and mice. (Yup; mice like nesting in feather mattresses)

And yet, despite these far more serious aspects, I think we would all have major hang-ups on the clothes - at least to begin with.

Dear male reader: Forget about boxers. Instead, your undergarment is a linen shirt that reaches almost to your knees. The sides of the shirt are slit up to hip level, the cut of the garment is ... err ... rather unsexy (no slim fit). On top of that, you'll wear this shirt night and day for one, two, three weeks, and as a replacement for those boxers you no longer have you simply pull the back end of the shirt up between your knees and vice versa with the front, creating a primitive onepiece. As I said; not very sexy.
Your shirt is complemented by stockings that end over your knees and are gartered to keep them from sliding down to reveal a hairy shin to the world. The outfit is completed by breeches (one, perhaps two pairs at most) in a practical dark colour. Not black - black is expensive to make, expensive to keep clean - only the well off can afford black. No, aim for a brown or a grey, perhaps a dark green? If you're middle class you'll have a doublet or short coat that matches your breeches, and maybe you'll finish all this elegance off with a white, starched collar and matching cuffs. And you will always wear a hat - always.
For cold winter days you might have a cloak, if not it's just a matter of wrapping up in as much rags as you can find. On your feet you'll wear shoes - the more well off wear shoes with metal buckles and heels. 
There; fully dressed. There is a stain of something dark and gooey on your breeches. Your doublet is wearing thin at the elbows and smells of sweat and smoke, of the beer you accidentally sloshed over your sleeve three days ago. Your stockings itch. The coarse linen of your shirt causes patches of irritated rash. I bet there's not a day when you don't long for tee's in cotton, for jeans and oxford shirts. Tough. You're here to stay...

Dear female reader: It's often said that men whine much more than women. Take a sick man, for example. One might think he's on the verge of dying as he lies on the sofa and complains about his runny nose. It's the same in this case; your male time traveller companion will moan and complain, and yet he's the lucky one - at least when it comes to clothes.
Anyway, let's start with the shift (or chemise). A long linen garment that reaches halfway between knees and ankles, it has long sleeves and a neckline with a drawstring. It falls straight - no frills - and serves as combined nightie and underwear. Forget about a silky negligee when you're in the mood for some action - no honey, you have to make do with this piece of unbleached linen. (I'd recommend using nudity for seduction). This shift of yours is worn until it can almost stand on its own - laundry is a heavy, onerous task, and as a woman you're all too aware of the backbreaking labour involved in getting the linen clean, ergo you wear it for as long as possible. 
On top of the shift you wear stays. Okay, so they're not as bad as those sported by Scarlett O'Hara, but once you've laced them you'll feel somewhat inhibited in your movements. Stockings in scratchy wool are rolled up your legs to well up your thigh and gartered into place. Petticoats keep you somewhat warm, and unless you're filthy rich they'll be of a practical length ending just above your ankle. Heavy woolen skirts, a bodice (with or without sleeves. You can mix and match sleeves) and an apron. While your skirts will probably be brown or so, you might splurge a bit on the bodice - purple? bright green? 
At this point you stop to inspect yourself - you have a small looking glass, lucky you. The collar is tied into place, your hair is braided back and coiled into a tight bun and with a little sigh you cover your head with the obligatory linen cap. A woman without a cap is a sinful thing indeed! One last look in the mirror; oops, an escaped tendril of hair is shoved into place. You twirl - you always do, as the single nice thing about all these clothes is how your skirts lift when you do that. By the door are your shoes - if you're lucky they might be a pair of latchet shoes, but they might just as well be clogs. Actually, maybe using clogs is the better choice - at least they keep your feet dry!

Right at the top of this page (to the right) you'll find a little short story that illustrates period clothing a bit further. Enjoy.