1. Log in to your blogger account.Go to design >> page element>> Add gadget
2. Select HTML/JavaScript and paste below code and save it.
<div align="center">
<table bgcolor="#000000" border="0" cellpadding="2" cellspacing="6" width="265">
<tbody><tr>
<td><center><a href="YOUR ADS URL HERE" rel="nofollow" target="_blank"><img alt="AD DESCRIPTION" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2ueyUKPkivS-pqQhQdfEIwyJ5Gd88O9fCegEu1L9m97c6IVb8H3-i1LoSRBECLwVD3O4fmOrKPC_XCzJHuHce-iuFmuhqC4VbTk6T9yGOIGBeVH-IxDTkrrMMCNUN0LgU1tA_WP4jf44/" border="0" height="125" width="125" /></a></center></td>
<td><center><a href="YOUR ADS URL HERE" rel="nofollow" target="_blank"><img alt="AD DESCRIPTION" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2ueyUKPkivS-pqQhQdfEIwyJ5Gd88O9fCegEu1L9m97c6IVb8H3-i1LoSRBECLwVD3O4fmOrKPC_XCzJHuHce-iuFmuhqC4VbTk6T9yGOIGBeVH-IxDTkrrMMCNUN0LgU1tA_WP4jf44/" border="0" height="125" width="125" /></a></center></td>
</tr>
<tr>
<td><center><a href="YOUR ADS URL HERE" rel="nofollow" target="_blank"><img alt="AD DESCRIPTION" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2ueyUKPkivS-pqQhQdfEIwyJ5Gd88O9fCegEu1L9m97c6IVb8H3-i1LoSRBECLwVD3O4fmOrKPC_XCzJHuHce-iuFmuhqC4VbTk6T9yGOIGBeVH-IxDTkrrMMCNUN0LgU1tA_WP4jf44/" border="0" height="125" width="125" /></a></center></td>
<td><center><a href="YOUR ADS URL HERE" rel="nofollow" target="_blank"><img alt="AD DESCRIPTION" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2ueyUKPkivS-pqQhQdfEIwyJ5Gd88O9fCegEu1L9m97c6IVb8H3-i1LoSRBECLwVD3O4fmOrKPC_XCzJHuHce-iuFmuhqC4VbTk6T9yGOIGBeVH-IxDTkrrMMCNUN0LgU1tA_WP4jf44/" border="0" height="125" width="125" /></a></center></td>
</tr>
</tbody></table>
</div>
3. after this you can sign up buysellads.com and link with your ads.
4. Replace your ads link with YOUR ADS URL HERE words.