Can I integrate with Salesforce to collect and update contact data?

Sure you can.
If you are using Salesforce to collect your contact details then, like using any other CRM, you will need to constantly update your information.
Many organizations and companies find themselves updating their data base manually, because they don't know of or cannot find a good tool to automate this process with.
The best way to do this is by using a web-to-lead form (in your website, or even inside Salesforce) to collect the data and set up an integration with Salesforce that will update this information in the relevant objects.

The perfect solution
FormTitan, which has a powerful integration with Salesforce is the perfect solution for this task. It can seamlessly connect to your Contact object (as well as many other objects) to create new contacts and as well as update existing ones.
So when the form filler enters data and submits the form, it is not only stored in the FormTitan data center and an email is sent to you containing the data - but it is now also pushed to your Salesforce account.
Read more about the SF Push integration
Read more about updating data in Salesforce