Can I use the Services module without coding skills? I'd like to create an xmlrpc endpoint to import (add, update, delete) users from one Drupal site to another and believe that the Services module is the right tool for the job. However, by reading the documentation and looking at the screencasts out there, it seems to me that it requires some coding skills (like the Migrate module) in order to get the most out of this module.

I'd like to know if I could import my users with this module without any coding skill or if it requires more developers skills.
Using migrate and services are for separate use cases IMO. 

I'd use Migrate for a one-off or periodic import and use Services for RESTfully add/update/deleting one at a time. 

The services module includes integration with the user module and you can pretty much administer/point and click to get an xmlrpc endpoint with the user resources added. 

You'd have to write a bit of code on the first site though, you might use a user hook http://api.drupal.org/api/drupal/modules!user!user.api.php/function/hook_user_insert/7 (or update, delete etc) and then use the data to make a http request to your other site http://api.drupal.org/api/drupal/includes%21common.inc/function/drupal_http_request/7