If I was to signup with office 365 and their hosted sharepoint server, would I be able to create a sample project that could demonstrate to a potential employer that I have the skills?
i.e. I currently do contract work .net/mvc/etc, but I want to get into sharepoint but remain as a contractor. Realizing this, I need some sort of an example project to show that I can do this type of work
Any suggestions? Is this a good idea?
Yes, You can.
You have to create a app using your development skills and deploy the App to store and from their you can give the demo.
Yes, as Waqas mentioned you can create an APP and add it to a SharePoint store and then showcase it to your perspective clients. But that's just a small portion of what SharePoint can do. I used to do heavy C# SharePoint since 2007 but last two years its mostly JS and client side code. Its a big shift, and most work will be on a client side these days in office 365.
Thus i would suggest:
Learn how to brand a sharepoint site, nothing turns off a client than OOB SP Site
Create custom webpart/s that showcase your client side (JS) skills.
Learn about provisioning and list creations. Content Types and possibly Document Sets.
If you have a custom iis/azure server, create your own timer job/ or rest service and consume it from SharePoint.
Good luck.
