Getting started.
I thought I would start at the beginning, because not everyone has used a vacuum sealer, and some have had poor experiences with one.
Meet my Foodsaver.

This is my second machine, and by today's market it is an older machine. My first one never died, I just upgraded when the opportunity came along.
Points to note:
The vacuum chamber is the area inside the black gasket. Sometimes fluids will seep into it. This area needs to be cleaned after each use with warm soapy water and a paper towel.
The heating bar can get too hot if you are doing a lot of bulk sealing. This can cause the bag to melt a bit and seal prematurely. The way to avoid this is to seal each bag as it is made ready rather than waiting until the end and sealing them all at once and to seal them with the channels up.
These vacuum bags have tracks, or ridges, in them that give the air a channel to follow. This helps prevent the item you are sealing from trapping air in the bag.
Let's seal some chicken!
I picked up 4 whole fryers @ $.79/lb. I could keep them whole and make chicken roasts, but that doesn't work as well with my family. Time wouldn't permit for me to pick up more so 4 will have to suffice for now.
I cut the chickens up into their respective pieces of breasts, thighs, drumsticks, and wings. I'll freeze the carcasses and necks to make stock on my next weekend off. I didn't vacuum seal those since they will only be in the freezer for less than a week.
Start by sealing one end your bag.
Take the edge of your first bag (while it is still on the roll) and lay it against the OUTSIDE of the gasket.
Close the lid, lock the sides, and press the button.
The indicator light will come one once the vacuum chamber is evauated. When the light goes off, the bag is sealed.
TIP: If the chamber seems to be evacuated, but the light hasn't come on to seal the bag, press down lightly on the center of the front bar. There might be a small gap and pressing down the front bar will close it.
I always double seal the ends of my bags. This is because most things we seal have water in them. Water EXPANDS when it freezes, and will sometimes rupture the first seal. Double sealing adds a layer of insurance.
Move the edge of the bag up over the gasket and repeat the process to double seal the bag.
Next, lay out the items you are going to seal and roll out the bag to measure the length.
This picture shows my drumsticks will take 4 "notches" for the meat, and I leave 1 notch for my headspace.
TIP: Just like with canning or container freezing, head space is critical to a proper seal. Without it, the bag will draw down and then pull out of the machine before it seals. I usually allow 1 notch for headspace.
Next, cut the bag to length. You don't have to use a fancy paper cutter like me, scissors work just as well. I used to use a ruler and mark my line in sharpie then cut it with scissors.
Label your bag. If you use labels like I do, either printed or label maker, place the label on the smooth side of the bag. This gives the label and even surface to grab onto. Now don't rush out and buy labels or a label maker. Up until about a month ago, I used a plain ol' sharpie. Write on the smooth side of the bag.
TIP: It's easier to label a smooth bag than one that is already packed and sealed.
NOTE: I put my chicken out six months. Some may not agree with that, and that is fine. This is a judgement call, and the FDA has some good guilines regarding food safety. I personally have had no problems with this timeline. This chicken will probably not be in the freezer that long, but on the off chance that one of the bags gets lost at the bottom, I still have a few months to "discover" it!
Pack your bag, and place it with the edge over the vacuum chamber's gasket. Be sure to place it with the ridges UP.
Close the lid, lock the sides, and press the button.
Point to note: My left hand has been handling the outside of the bags and the machine, my right hand has been handling the chicken. That's why it is always closed and I touch the machine with the outside of my hand. It's one of the those habits I developed over the years, but it does help me to avoid cross contamination when handling meats. Also, don't rush out and buy latex or nitrile gloves unless you are squeemish or are germaphobic (like me). The gloves make handling the meat easier for me.
Next, you'll see the bag evacuate, and even some fluids being drawn up into the channels. If this doesn't happen, then there is a gap around the gasket of the vacuum chamber. Open the machine and make sure there isn't debris on the gasket, the gasket is seated properly, and the bag is in the proper place.
As you can see in the picture, the corners of the bag are being pulled because the slack in the bag has been drawn down over the meat, simply push the bag toward the machine to give the bag some slack. This is where a lack of head room would have the bag pull out of the machine before making a complete seal.
Now pull the edge of the bag back to just outside of the gasket, and seal again. This gives the edge a double seal.
NOTE: You can see where some fluids were drawn up into the channels. This is nothing to worry about. If it got drawn into the vacuum chamber, clean it up with some warm soapy water and a paper towel.
And now we have a neatly sealed bag of drumsticks!
It really is that simple!
I repeated this process until the whole lot was finished and placed them FLAT in the freezer.
I will wait for another packet of wings to make BBQ'd wings, the thighs I will turn into 8 qts of chicken soup once the stock is finished. Also, I have two 4 packs of breasts and an 8 pack of drumsticks. So by vacuum sealing and canning, I turned 4 meals into 7 1/2 for a family of 4. I could stretch it further if I cubed the breasts and used them in stir frys. These breasts are huge and would only take two or three for a stir fry.
If you are considering vacuum sealing, or you have had problems in the past with it, I hope this has helped answer a few questions.
FOOD SAFETY NOTE: Please clean your machine before and after each use. I put a cap of bleach in a 1 qt. spray bottle. I clean the counters and the machine before I start, and once again when I'm finished.
Credits: Pictures courtesy of DD2(13).