If you're looking for a detailed guide for integration of WFMCRM please review this technical documentation.
WFMCRM for Salesforce Professional Edition (PE)
How To Buy WFMCRM
WFMCRM is available on the Salesforce AppExchange.
To access the App, go here: https://appexchange.salesforce.com/listingDetail?listingId=a0N30000000rIqTEAU
The app can be downloaded directly from AppExchange as a managed package.