Basic PPC(pay per click) tool

1)Google Adwords

https://accounts.google.com/ServiceLogin?service=adwords&cd=IN&hl=en_IN<mpl=regionala&passive=true&ifr=false&alwf=true&contin-ue=https://adwords.google.co.in/um/gaiaauth?apt%3DNone

https://adwords.google.com/o/Targeting/Explorer?__u=1000000000&__c=1000000000&ideaRequestType=KEYWORD_IDEAS#search.none
https://adwords.google.co.in/o/Targeting/Explorer?__u=1000000000&__c=1000000000&ideaRequestType=KEYWORD_IDEAS
http://www.vertster.com/adwords-tool/
https://accounts.google.com/ServiceLogin?service=adwords&hl=en_US<mpl=regionalc&passive=true&ifr=false&alwf=true&continu-e=https://adwords.google.com/um/gaiaauth?apt%3DNone
2)MSN AdCenter
http://advertising.microsoft.com/small-business/support-center/adcenter-downloads/adcenter-desktop
https://adcenter.microsoft.com/
3)Yahoo search marketing
http://advertisingcentral.yahoo.com/searchmarketing/international
http://www.pixelfast.com/overture/
http://antezeta.com/news/yahoo-search-marketing-tools