Hi, I've had a quick look at your site and have some very quick initial feedback.
The first thing that strikes me is that you're branded as a marketing company but you're selling products.
I imagine the intention is to sell a diverse range of products which is fine but I'd suggest setting up dedicated microsites for each specific range of products or specific niche ie Bannerman Adhesive or Bannerman Automotive etc.
Focus can help no end with your
SEO efforts because the search engines will look at site descriptions, keywords, titles, content and links (to name but a few) and they like to see a common thread.
When you go through to your e-commerce area the global navigation at the top of the page changes and the home link takes you to the shop homepage rather than the site homepage. This isn't necessarily a problem but you should make it more obvious that you've navigated away from the main site because at the moment it will impact the user experience.
One final observation is that when you go to the registration page of the shop users are asked to enter some personal information but the site isn't secure. You might find that even at that early stage people are looking for a padlock symbol and https in the URL.
I suspect I've just given you an unexpected chunk of work but as you said half the pleasure is in the learning.
I hope I've helped a bit,
Adam