My company is newly implementing Salesforce. I would like to know the way on how to integrate the marketo and salesforce. Any guidance or useful links could be helpful.
It looks like there is already existing app in appexchange for integration with Marketo. Checkout below link, http://pages2.marketo.com/rs/marketob2/images/Marketo-and-SFDC-for-New-Customers.pdf
Marketo is pretty tightly integrated with SFDC using the Marketo app on Appexchange. Marketo support will help you out if there are any questions regarding integrating with SFDC using Marketo App.
There are business cases which result in duplicates in SFDC and Marketo. In Marketo email addresses are treated as unique. There are cases where some customers of mine had to have duplicate email addresses in SFDC to support their business processes such as support and different business units etc.
There are quite a few gotchas and lessons learned. Don't want to put it all here as it is long. Please reach out if you need more info. Rajesh [at] BrightAspects.com