Schwinn Mountain Bike

Steven gave a nice answer, too bad it is for motorcycling.
I moved from the Southwest back to the Pacific Northwest a few years ago so here is what if have found in my efforts to become waterproof:
1. How do I keep my head warm and dry while still wearing a helmet? Is it unsafe to put something on underneath my helmet? If so, can I put something on over it? My helmet is vented and has a visor.
You can get a synthetic or wool biking cap for under the helmet, which will get damp but still keep you warm. The other option that I have not tried but see often is a helmet cover, which will keep your head dryer.
2. Please suggest a waterproof garment for keeping my face and neck dry-ish and warm.
Dry is probably not a complete option here. I have found if you use a helmet with a visor that helps a bit. A synthetic/wool baklava or neck gator, will keep you warm if not completely dry. I use the same one I got for snow skiing.
3. Is there such a thing as waterproof shoes? If so, list brands if possible. If not, suggest how I may keep my feet dry and warm. Brands are helpful.
I have heard positive things about Lake Winter Boots. http://commutebybike.com/2008/09/28/lake…
They are not cheap. None of the rain proof shoes are.
I use my regular biking shoes with shoe covers. Which you can get for $30-50. I have Sugoi (Link Below) Keeping your feet dry is a challenge. The hardest part is keeping water from wicking its way down your socks from the top of the boot. The best defense is too accept, especially on a long rainy ride, that they will probably get damp. Wear a good pair of wool socks as they will stay warm when wet.
4. I am assuming I will also wear a waterproof jacket, waterproof pants (perhaps Gortex, but can you suggest a cheaper-but-still-reliable brand?), and gloves. Specific brand suggestions are helpful.
Pants first. Riders go two routes. First, you can wear heavier lyrca. This acts like a wetsuit on a diver. You may feel a bit damp. I usually don’t notice it. But you will stay warm. The main drawback I find with lyrca pants is that it is more difficult to keep my feet dry as the water is more likely to seep/wick into the top of my boot cover. Second get waterproof pants. I have a cheap pair from REI and they have been durable and effective for a few years now. They shed water well and when I place them over my shoe covers my feet stay dry for a very long time. The drawback is they have little or no ventilation so they can get hot and sticky. If you don’t get overly warm when riding then these are the driest option.
Jacket: I have a Showers Pass Double Century Jacket and I love it. The best thing about it as a jacket is you can adjust the ventilation with armpit zippers and cuff straps. If you are looking for something cheaper, I think you can get a Novarro rain jacket from REI for less. If you are looking to save some $$, Don’t go for Gucci breathing materials. Go for good venting options on the jacket. Good venting makes a much more significant difference than breathing material. Especially when it is raining.
5. Suggestions on where I can buy these things for cheaper (I already know I can look on E-bay).
If you are into bike commuting for the long haul buy your clothing out of season. I jet my jackets/winter gear during spring clearance and right now/last fall I’m watching for any summer riding gear that is being dumped.
BikeNashbar and Performance bikes can often yield a good deals.
I also save my searches on ebay and just be patient.
Last year I picked up a couple of Nike and Canari marino wool long sleeve jerseys on ebay. They are awesome for winter riding. I wash them maybe twice a season as they never smell like synthetics and are really warm when its wet.
Finally, if you hang around or work on a computer, try a site called Chainlove.com They sell one item at a time, usually at a very steep discount. You can have them e-mail or alert you when a new item comes up for sale. Often I see women’s jackets and clothing listed. If you are an impulse buyer, maybe not a good thing but I have managed to control myself and have picked up things I really need with very good savings.

Go to the site below.They have anything you need.Forget ebay.

Sorry, I had to laugh at this question. For me, dry is not possible. Even If I could keep the rain out, I can’t keep the sweat in. I’ve come in from a ride and had people ask if its raining….. and it’s not! Ambient temperature doesn’t matter. If I go over 11 mph, I’ll be drenched when I get where I’m going rain or shine.
I’ve got showers at work, so I just carry a change of clothes. If I didn’t, I would look for a gym, YMCA, health club, or other shower option within walking distance of the office.

1. How do I keep my head warm and dry while still wearing a helmet? Is it unsafe to put something on underneath my helmet? If so, can I put something on over it? My helmet is vented and has a visor.
There are hoods made specifically for this, check out http://www.boomboomcycles.com
2. Please suggest a waterproof garment for keeping my face and neck dry-ish and warm.
again try boomboomcycles.com
3. Is there such a thing as waterproof shoes? If so, list brands if possible. If not, suggest how I may keep my feet dry and warm. Brands are helpful.
http://www.LLBEAN.com duck boots, they are the warmest waterproof boots you can buy
4. I am assuming I will also wear a waterproof jacket, waterproof pants (perhaps Gortex, but can you suggest a cheaper-but-still-reliable brand?), and gloves. Specific brand suggestions are helpful.
I really love the first one below but it budget minded the Triton works great.
Hein Gericke PSX-R Textile Motorcycle Jacket … $103.95 – Sierra Trading Post
Scorpion XDR Shock Waterproof Jacket $389.00 – Motorcycle Superstore
Triton SS Waterproof Jacket $179.95 – DSR Power Sports
5. Suggestions on where I can buy these things for cheaper (I already know I can look on E-bay).
http://www.motorcyclecloseouts.com < best of the best and cheap!

to start, there is nothing totally water proof. if it is really raining, you are going to get wet, but you can be wet and warm. a gortex jacket and pants takes care of your body and is worth every penny you pay.
now your feet, hands and head are problems. most shoe covers are neoprene which keeps you warm but still get wet. same goes for gloves, hats and masks. they are usually either polypropolene or wool. keeps out the cold, but you still get wet. sorry, but i know of no like totally waterproof stuff for your head, hands and feet.