One of the easiest way to transfer your data from one site/server to another site / server would be saving the site to template. But the catch here is by default the maximum size of the template should not exceed 10 MB(10485760 Bytes).
If you try to save any of your large Site as Template, you might get the following error
"The site is too large to save as a template. The size of a template cannot exceed 10485760 bytes. "
This can be solved by just increasing the maximum size of the Template
stsadm -o setproperty -propertyname max-template-document-size -propertyvalue 20971520
Note: 20971520 bytes = 20 MB, Maximum Size you can set is 500 MB