You can try for free, with annual licenses costing just £240 per user. Then increase the number of users (up to 10) for your team or upgrade to Professional or Enterprise editions depending on your particular needs.
If you are a Registered Scottish Charity, you already qualify for 10 donated Salesforce Enterprise Edition licenses from the nice people at Salesforce.org. Essentials edition doesn't therefore apply to you.
Contact management, sales and customer service
Salesforce Essentials Edition allows you to manage records for contacts, organisations, sales opportunities and customer service enquiries. Let the team log all their activities (tasks, meetings, calls) so you all know who did/said what/when for a customer. Log important emails directly from Microsoft Outlook. Then view your data roll up into nice colourful dashboards. And view and manage it all through he Salesforce mobile app on your iPad or smartphone, if that works better for you.
You might actually find that Essentials Edition is all you need going forward, so you could end up by completing a low-risk experiment resulting in a very cost-effective CRM platform for hosting your business records.