need help about arduino uno+ethernet module+tp link wireless router

hey guys um a beginner and i need help with controlling arduino through wifi,i have old wireless router ( TL-WA501G) and i want to use it to control 4 output digital pins, i already know that i need ethernet module(ENC28J60) and ethernet library and my notebook has wifi network. so all i know is i need to change mode of ap to client mode and i already changed it but what next ?? i appreciate ur help

So you've changed the mode on the router, the next step would be to test it with a computer, to verify that it works as a client. Once that's done, start getting the parts and working through some of the examples. There are PLENTY of examples that involve controlling digital pins with over an ethernet connection. I would however, getting a Wiznet W5100 based ethernet shield for beginners. You're also going to need an Arduino to plug the Ethernet Shield into and actually load and run the sketch.

well my laptop reads it but how to use my laptop wi fi to control arduino?? do i need application to control it ??? iam stuck in the middle :(

Google "arduino control led over internet" and I'm sure you'll find plenty of examples

If you are a beginner, you need to get the w5100 based ethernet shield. Below is some simple tinkering to make a routerbot that might be useful.

thanks :)