You should be able to just edit the blockquote style in your style.css file for your theme to customize blockquotes any way you want them. For instance, mine looks like this:
#posts .post blockquote, #posts .page blockquote{ padding-left:45px; background:url(images/blockqoute.png) top left no-repeat; font-style:italic; min-height:35px; color:#999;}
Note that this code will be different depending on what theme you’re using but it should be similar enough that you can find it in your stylesheet.
If you’re wondering how to edit your stylesheet: go to your wp-admin, click on ‘Appearance’ then click on ‘Editor’. Your stylesheet usually shows up in the editor by default. If not, the list of your editable templates is on the right hand side of the editor (style.css is usually the last one in the list).
Hope this helps
