Hello, I’m trying to find a good antenna to extend the range of my wireless network. I don’t know how to choose one. What im trying to figure out is the maximum distance that a particular antenna can radiate signals according to its transmitting power, antenna gain, and frequency. For example im looking at an antenna with a power input of 200mW and a 7dBi gain at 2.4GHz. That is all the information that the manufacture gives.
You don't say whether you wish to increase all round coverage or just in a particular direction.
Have a look at this comparison chart to see how the directionallity varies, be it in the horizontal or vertical with gain :- http://www.solwiseforum.co.uk/downlo...comparison.pdf
Depending on where you live you will have to look at the legal requirements, regarding the EIRP of your system, and as you increase the gain of your antenna you may have to reduce the transmitter output.
A WiFi system does not just rely on your eqpt for communications but also on who you are connecting to, so their installation has an effect on the distance and the Data Rate you are using.
How to choose an antenna? 
For example im looking at an antenna with a power input of 200mW and a 7dBi gain at 2.4GHz. That is all the information that the manufacture gives.
Linear Mode
