The real big danger with backfeeding is even if you know how to do it safely chances are good that not everyone in your home does. There are lots of horror stories on the net about it, not only it killing linemen (those pole top transformers work both ways, stepping down high voltage, or stepping up low voltage if you backfeed), but also family members that try to turn the breakers back on while "dad" is away for a few minutes when power comes back on.
To generator advice there has been a lot of good stuff mentioned, but I will say a bit more, first of all there is a lot of JUNK on the market, much of it with what is otherwise reputable brand name labels. Often these companies don't make generators, they just put their names on them, not only is every bit of quality often sacrificed in the name of price, but their is often no parts available to repair them.
Now down to specific suggestions, if your going to buy a small gasoline powered generator, but either a Honda or a Yamaha, they cost more but are worth it. Note not all Honda's are Honda's, you have the REAL honda brand generators, then you also have "powered by Honda" which just means it is a Honda engine connected to someone elses generator end.
If getting a home stationary generator avoid Generac, they may be the number one seller, but a lot of that is based on 2 things, low price, lots of money spent on marketing to tell everyone how good they are. Instead buy Cummins Onan or Kohler, again up front it may cost you more, but you will not find likely be finding yourself on a first name basis with the generator repairman at $300+ per visit.
On the topic of interlock kits, they can be a cheap alternative to a transfer switch, just check with your local authority to see if they are allowed where you live. For better prices check this brand out
http://natramelec.com/
