Create a text document and write an ad and contact information. This will allow you not to spend too much time in the future, then you're going to copy and paste text on websites.
Post an ad on specialized sites. These are the sites go by your potential clients.
For example, if you sell the car, place ads on the websites:,,,
Post an ad on sites of your city, because your offer is likely to take advantage are the ones who live nearby. For example, Samara is to Ekaterinburg
Post an ad on a major Federal sites. They have, as a rule, very large attendance and high positions in the search engines, so your offer will see a lot of people.
Here is a list of the major portals:,,,
At each site, look for "Submit an ad" and click on it. Enter the registration information and advertisement. To you to the email Inbox from all sites will be notified about placement and link to your ad. Also, in such letters typically provide information on how you can edit your ad, your login and password to access the site.