Great question! I’m not much of an artistic type myself, so when I look for inspiration I often look at the web design section of dribble. If you search for keywords such as “user-interface” you’ll find things like:
Which I find to be very helpful to get me started. It’s a great resource. If you’re looking for a useful overview, check out this article. It has useful and practicable information and a dozen or so useful resources at the bottom.