Customer Relationship Management Software (CRM) is a package that allows you to record and store customer and /or supplies details. These systems can vary substantially in not only price but the amount of information you can put in and get out of them.
If you run a small business, it may be that you do not require the larger CRM software programmes such as ACT! (part of Sage Accounting), but do need something to keep track of your clients.
Firstly you need to compile a list of information that you either hold on your customers or could obtain quite easily. Next you should detail all the things you currently want to achieve from the marketing software (e.g. sending out email newsletters or mail shots) and may want to in the future. This will give you a basis to start from; you can then start to look around at the different software and packages available to find out which one will suit you and your company.