The answer depends on southwest of WHAT and since you have not bothered to provide that crucial bit of information, it is not possible to give a more useful answer.
The plane's seats...
Depends on what kind of plane you take. I have been on planes that have as few as 6 seats, and as many as 300.
Southwest is adding wifi to more planes all the time. They don't expect to have wifi on all flights until 2012.
737
Boeing
No, Southwest does not allow dogs on their planes, unless you have special needs.
planes
Yes, some planes have over 200 seats.
none of the above.
The time I sat in that row, the seats did not recline. They were uncomfortable. I try not to sit in them.
Some airlines that offer lay flat seats on their planes include Delta Air Lines, American Airlines, United Airlines, and British Airways.