Start by sorting out the markup errors. Then move onto the CSS errors.
http://codex.wordpress.org/Validating_a_Website
If you continue to have problems with IE, consider conditional comment CSS
Hey Esmi, would you perhaps be willing to fix it for me (depending on your fee, of course). I’m not much of a programmer and I’m a little stumped here.
If you need to contact me privately, please see http://wordpress.org/support/profile/esmi
Incredibly a friend of mine managed to fix it! Thanks anyway for for being prepared to help, much appreciated.