Can the £100 be used on an Adwords Express campaign ?
This is a really easy introduction into adwords and is very easy to set up, you don't get the options available with normal adwords but it will give you a introduction while you research how to run a full campaign
I think the biggest mistakes is not setting geographical limits, make your ad only show with 15-20 miles of your address, I see adwords which are from companies 200 miles away.
Also make the landing page relevant to the adwords headline
'Birmingham suite cleaners' should go to the suite cleaning page on your website not your home page.