Create an account at one of those pools, go to "my account - my workers", add new worker (workername & pw). Then go to "Help - Getting started", choose a miner, for example cgminer (depends on your videocard, geforce / amd), download the miner and extract all files to a folder. Create new textdocument in the folder, rename to start.bat, edit file with editor and copy the line from "Help - Getting started" into the file, for example
cgminer --scrypt -o stratum+tcp://mastermining.net:3214 -u Weblogin.WorkerName -p WorkerPassword if you want to mine at mastermining pool using cgminer, change "Weblogin.WorkerName" to youraccountname.yourworkername and fill in the workerpassword you set before. Save file and execute.