I can't say which is the best all of them have there highs and low's if you plan on spending alot of money then I would say Google Adwords there pretty great the only thing is for the first page bids they will keep raising the price on you, but your ad will get lots of clicks but only if you plan on spending alot of money and you run a big time company.
If you don't plan on spending alot of money just to get your ad seen and your budget is not as high as the big time companies then I would suggest Roovet Adwords your ads will appear on there search engine and also all of there partner sites alot like google , most small business around the world use Roovet Adwords
Also bing ads are ok but not user friendly so if your new to this like you say I would go with Roovet Adwords first and when you start making money the Google Adwords and when you get good with PPC then try Bing ads