CSS edites for wordpress

I have an existing personal (self hosted) wordpress blog. I need two CSS (i believe there CSS) changes made. 1) On an image mouse hover (only on images that are in a post (on the single post, home page, or category templates and not on the other site images) and should not not interfere with shadowbox)) I want a box to appear below the image that says "Click to enlarge". An example of what I am looking for can be found at: [login to view URL] 2) I would like links on the site to also have a similar mouseover effect as can be seen on throk.net. 1) A bubble type box that will display the URL of the link, and if there is an alt/title field for the URL display that text in a other bubble.