Make my WordPress template editable by someone with limited WP skills

Hi, thanks for looking. I'm not sure about the budget as I have no idea of exactly how much work this will involve, but I want full (if possible) control over my website (as a non-techie). Currently I can change text on the pages (within the design constraints of the Template) but I can't edit the menu elements, the images, the links from the Template images, the Template images themselves (for example to highlight attendance at a Trade Show) or the side links on my web site - many of which are now well out of date. I also have a plan to make the site mobile friendly by identifying when a user is accessing via mobile device and switching them to the .mobi URL I also own. I am looking for ideas please. I know there are a lot of great people around who do this stuff out of the UK, but for now, I would like to limit this bid to UK only. Again, many thanks for looking, Andrew