1. First make sure that during installation you have the following settings activated in your drupals settings.php and my.ini or my.cnf files: Add ini_set('max_execution_time', 500); to your settings.php. In your my.ini or my.cnf you should have the setting of max_allowed_packet = 16M otherwise it could happen that agreservations not installs completely, especially the agres_categories module needs some time to install all the fields. Very important: Use clear urls!
  2. install the required modules: references, user_reference, node_reference, date, date_views, views, ctools, i18n, date_api, date, date_views date_popup, uc_cart, uc_product,...
  3. install the agreservations modules:
    • agreservations, (core)
    • agres_bookings (Ubercart Integration)
    • agres_categories (online booking widget)
    • agres_views (booking calendar) 
    • Agreservations Timeframe (not yet in version 7.x-1)
    • Agreservations Restriction (not yet in version 7.x-1)
    • Agreservations Rate (not yet in version 7.x-1)
  4. add at least one node of type agres_category like: hotel room, car, table,...
  5.  add at least one (or more) agreservations_unittype like: standard,  large,...if ubercart is enabled: in the ubercartshopconfiguration at  http://yoursitesurl/admin/store/products/classes make this contenttype  a productclass.
  6. In the Unit Type nodes now you can set the Ubercart price and sku fields.
  7. Assign a category to each unit type.
  8. add some agreservations units like: Room #1,Room#2, boat1,...
  9.  the module contains a default view bookingcalendar which should be  installed automatically. When you followed the above steps you should  see a matrix of resources and units when clicking on the Agreservations menu link.  You can click on the little '+' signs  for each day/room and make a booking, you see the agreservation form prefilled  with the correct day and room you clicked on. You can choose more rooms of course.
  10. each node of type agreservations_category creates a searchwidget Block which you can activate  in Administer->blocks. This is for the frontpage for users to make onlinereservations.
  11.  Activate / deactivate the appropriate cart and checkout panes in the Ubercart configuration also configure your Ubercarts order templates.

Additionally view the video demonstrating in short how to set up the agreservations online booking sytem