To get an ad on Google you can do it by calling their 800 number or going to AdWords. You can place your ad for free and only pay for when someone clicks on the ad.
Register for google adsense account
you can but you have to send it to youtube/google and pay them to advertise your website
So that they have more users, so that they can advertise more.
There are quite a few advantage to advertise when using this website ads. One is you only have to pay the company when someone clicks on your ad. Also, you can choose where you want your ad to be placed.
You can advertise a website any where you wish. Eg. Google, Facebook, Yahoo and many more. :)
Using Google's Adsense, you can advertise across the internet. You utilize keywords that are related to what you are advertising. When people search for these same keywords using Google, your ad appears.
You can use Google Adsense and Google Adwords. Advertising on GMail would cost you heavily.
Its depend on your keyword and your target area . search in google ad word .
I don't think there is any way for you to advertise for free in Google. The only way I can think of would be to SEO your site (white hat only - black hat gets you in trouble later) to try to get more organic Google search traffic.
There are many ways to advertise your business, online may be the cheapest, if not free way to do it. Make sure you are listed in Google's search, consider placing Google AdWords, advertise on CraigsList and set up a Twitter account to talk about your business.
Craigslist a great website where you are able to advertise farm equipment for sale.