First of all, to create your own advertisement banner - you should create a banner picture using an image editor (for ex: Photoshop).
Then you should share it on the Internet. You can upload the image to your network via Admin Area > Edit Theme > Graphics, and then use the following banner code by adding the link you received after uploading:
 
<a href="YOUR_SITE_URL"><img src="URL_RECEIVED_AFTER_UPLOADING" border=0 alt="SITE_TITLE" /></a>
 
To create a simple link - you can use the following code:
 
<a href="YOUR_SITE_URL">THE_LINK_TITLE</a>

So I shouldn't use Adsense with this? because it's not working at all now that I've added all adsense banners to it

It works with Adsesne, please provide a code you used.

When I add the code:

<a href="http://bluetax.com/" target="_blank"><img src="http://posdit.com/graphics/bluetaxbannerad.png" alt="Tax Resolution for debt over $10,000" width="100%" height="92">

..it works on all devices and computers.

When I add the code:

<a href="http://bluetax.com/" target="_blank"><img src="http://posdit.com/graphics/bluetaxbannerad.png" alt="Tax Resolution for debt over $10,000" width="100%" height="100%">

...the ad only shows on computers and laptops.

I'd like to know how to also make the height responsive and appear on devices. Please help. Thank you!