Logo/Header Picture and colours as well as downloads and sizes URGENT!

I've been looking around for OVER 3hours and I have found simalar questions but haven't found answers.

I would like to change: the arches and clouds at the top of my website:
https://www.personalisedpresent.com/shop

I would like to change that whole image so that the image located at:
http://i75.photobucket.com/albums/i281/dhblewis/logo.jpg

Also I would like to sell t-shirts. How do I get them to choose a size. Can I have a drop down boxes on product page??

Also I sell e-books. Is it possible to get them automaticly emailed to buyer??

I do apologies for all the questions but I have been extremly busy recently and need this done tonight.

Unfortunatly I amn't very good at all and would appreciate STEP BY STEP instructions

Many Many Many Thanks,
I really appreciate all your help.:smile:

Daniel

three "easy" steps:

1. create option name, like "T-Shirt Size"
2. create option values, like "L", "XL", "M", etc
3. add required option name-value pairs to every product in attribute controller (steps 1 and 2 are necessary before you can do that); here you can choose to price every size differently or keep the price unchanged
   refer to wiki for further info, or learn how it is done on test data that comes with installation.