How do I buy or make an incubator?

 How do I Buy or to Make an Incubator?
You can buy cheap incubators at feed stores or used on craigslist like the hovabator, (the white styrofoam ones) but I don't recommend it.  You get what you pay for and they do not have a very good hatch rate.  There are many things required in incubating like consistent humidity and temperature. Personally I think making a home made one (even with no experience) is the best bet.  Here are some different resources on building incubators.

1.  BYC (of course)-they have plans for anything from cooler bators to full size refrigerator bators--http://www.backyardchickens.com/chicken-coop-incubator.html
2. Here is a Youtube video to make a simple one form a syrofoam cooler.  http://www.youtube.com/watch?v=WQ1tyfvenqQ 
3. Here is a do-it-yourself article form Mother Earth News- http://www.motherearthnews.com/Do-It-Yourself/1982-03-01/Build-Your-Own-Incubator.aspx

After looking at several of these ideas/sites you will start to understand the main components of an incubator.  They are a Your box/shell, heat sources, humidity source, possibly a fan, possibly a thermostat, thermometer/hygrometer (measures humidity) and in fancy models, egg turners.

Putting Together a Homemade Incubator
The shell-of course the better if your shell it is insulated, the better it will hold a consistent temp and humidity, which is important for a good hatch rate. You can use old coolers, small fridges, I have even seen it work in a cardboard box!  Many people like to build in windows so you can see the chicks hatch.  An easy way to do this is to cut a hole in your shell, then take the glass from a 8x10 picture frame (or plexiglass) and silicone it to your shell.  At the bottom of this post are several pictures of home made incubator shells.
Heat source-the simplest answer is incandescent light bulbs.  The picture above is my home made incubator.  I use two 60 watt light bulbs in mine.  They are ran by ceramic lamps that you can buy at the hardware store.  My hubby mounted cords on them for me and installed them in the bator.   Heat rises, so it makes sense to install them low in your shell.
Fan-If you want a bator that will keep more consistent heat throughout, then you can easily add a small fan to circulate the air.  A computer fan works well.  You just have to splice a 12v adapter cord to the fan and mount the fan inside the shell.
Thermostat or no??- you can make do with just light bulbs and try different watt bulbs to try to keep the temp consistent all the time.  I prefer to use a thermostat.  The easiest and most reliable t-stat is the wafer.  You can buy them for about $20 at livestock supply stores.  I think I bought mine at Jeffers.  You just wire it inline to your heat source. Then to set your t-stat, you install your thermometer inside and plug in the lights.  You want your temps as close as 99.5 you can get.  Usually around 100 is good.  102 is too hot and 98 is getting cool.  So you adjust the knob on the t-stat until it stays at the temps you want.  You may have to readjust this periodically.  It is not justified if you are going to just hatch once or twice.
Humidity Source-this is a no brainer!  You just have to put a bowl or jar of water and maybe some sponges until the humidity is at 30-50%.  You will have to refill the water.  I check it every day.  IMPORTANT: when it is close to hatching day (day 21), please make sure the chicks cannot get into the water and drown.
Thermometer and Hygrometer-I bought mine at Walmart for $12. Here is a link to what it looks like;
http://www.walmart.com/catalog/product.do?product_id=15907746&findingMethod=rr
It has a probe on a wire that I put inside the incubator so that it can tell the temp and humidity while the unit is on the outside of the bator.  They work great!
Egg Turners- these are cool little things that will tilt your eggs for you so that you don't have to turn them 3 times a day.  (I swear by them!!!)  This really helps when you have hundreds of eggs!  I bought my turners from Jeffers.   If you are planning on having automatic turners, then make sure to accommodate for their size in your shell.  They plug in and slowly turn your eggs 40 degrees, 3 times in 24 hours. Make sure to turn the turners off for the last 3 days.