There are thousands of websites where you can get inspiration for digital and traditional art. Social networks have always been the first place to get inspired by other artists. Some following recommendations come from me which I have used or still use.
Artstation is by far the largest platform for digital concept artists in the industry. Artstation's one of the best websites serves as a source of inspiration.
On inspirationde i often found interesting designs and ideas in the past. The site has been updated many times over the years and is an absolutely good source of modern cover designs and general graphic designs.
Pinterest is one of the most popular and well-known sources for all kinds of creative people. Whether designers, artists or painters. If you are doing something creative you are in the right place for inspiration.
Weheartit is a great way to easily distribute your own work as an additional option to Instagram or Twitter. Weheartit is similar to Pinterest and has a lot of categories.
Tumblr has become more and more an underdog from year to year. Through tumblers some artists even became famous but Tumblr is still another possibility to spread your work or to inspire yourself.
Behance is a special case. It is not considered the most popular portal for art or design but besides Artstation it is a popular portfolio. For inspiration in the field of high quality work it is still a very good source.
Deviantart is well known by everyone who is interested in art and painting. For me, it is not my favorite platform but also here it is a possibility to spread your works or to look at other works.
Instagram is in my opinion currently the most popular network to get inspired. It is not only the most active network but also the biggest. The big advantage of Instagram is the possibility to exchange ideas and to write to artists. On many other networks you often don't get an answer because they are hardly online.
8. Google Images
The easiest way is sometimes the best. Google images is by far the fastest way to inspire yourself but you need to know what you are looking for which is often the problem. Not always you know what you are looking for if you want to be inspired. You have to be very precise in your search. My advice is that you think in keywords. For example: "modern digital art", "simple bird drawing outlines", "charcoal drawing digital. What I often use is the function "search for similar pictures" if I have a picture on my computer I let google search for it and see similar pictures immediately.