Theme development

i'm having a design put together for a website i'm working on but need help having it marked up for the drupal platform. i'm not sure if this is place to post about help - but if anyone is willing to lend a hand let me know. it's a compensated gig.

How do I theme thumbnails that gets created by using image_attach inside a teaser. I looked at my node.tpl.php and everything including text+image thumbnail is called $content. I need to float the thumbnail to left instead of right as it gets attached by default. There seems to be reference to a class "image-attach-teaser" and "image thumbnail"but couldn't find it. I need to make the teaser look pretty by formatting both thumbnail as well as text in a proper format.
So is there a place where $content is split so that I can modify the thumbnail image and text seperately?

I am a newbie to drupal and have ran into a bind. I have installed a theme in my themes folder and activated it. Well I went to another area in the site and then tried to go back the the themes section of site builder and started getting a fatal area...

Fatal error: Call to undefined function: form_render()

I am using the theme andreas01. Does anyone know how to bypass this and change the theme manually? Any help would be appreciated!

Using the Pushbutton theme, collapsible blocks collapse clicking everywhere in the block area, while they should collapse only when the click occours on the block title area...

I need some help here, pliz. I would like to move the header up more, the one with the blue background. See the image. I have managed to move up some parts of garland, but i am not successful with the header background yet.
http://tecito.com/images/temp/drupal_header.png
Thank you.

Can someone please walk me through how to add an icon to my aquasoft theme by modifying the style.css file? The directions:

The top toolbar icons(Primary Links) are customizable for each menu item. Refer to style.css for further information on how to assign icon for each item.

are a little vague. Here is what style.css says to do:

/* Specify Icons for each primary menu's menu item. */
ul.toolbarmenu {
margin-left:0;
padding:0;
}