Help Add Logo to Top Banner

I’m trying to put my logo (as a .gif) at the top banner while at the same time not deleting the blog title and tag line saved in the “settings/general” section.

I am editing it in the .css file under Header (using ProSense by Dosh Dosh theme), but I cannot seem to make my .gif appear in the right place. If it does pop up, I have to delete my original blog title and tag line so they don’t overlap, and if I do that, I no longer have a nifty Google search result which displays the name of my blog and tag.

Does anyone have any advice on how to display only the .gif of your logo in the heading while retaining the blog title and tag line for search result purposes?

Also, where is the best place to put this .gif within the header using HTML for left-aligned display? (I currently have it “on hold” using /*–)

#header {
width: 100%;
background: #000;
height: 120px;
background: #fff url(images/header_footer_img.jpg) top left repeat-y;
/*–url(‘images/logo_garage.gif’)no-repeat bottom left;–*/
}

Any advice or direct help is greatly appreciated!

Thanks.