Weekends can be viewed by going to "View" > "Gantt" > "Off-Hours" in the menubar.
As for the head-row issue, I'm not sure what you mean when you say they're gone. If they're showing up as "T+1 Day" then you'll need to set the project start date in the "Project : Information" inspector.
If you're just not seeing the day scale, you may need to click on the magnifying glass icon in the top right corner of the gantt chart and select "Days" from the list.
As for video tutorials, you can view them on our website here:
http://www.omnigroup.com/products/omniplan/videos/