If you've never heard of Freepik before, it's the leading search engine for free vector designs and the largest community of graphic designers in the world. Being a designer and not using Freepik is a crime, you get access to high-quality graphic designs, exclusive illustrations, and tons of user-based content, stuff you really can't afford to miss.
Freepik offers a freemium business model, which basically means that everything is free, you just need to credit the original creator in when using their work. Freepik's premium plan is a little bit different and definitely worth the little money it costs. With the premium service, you pay $7.50 per month for the ability to use as many images from them as you like without crediting at all (commercial or personal use). Also, as a 'V.I.P member' you gain access to illustrations which only premium members can download. You also get an ad-free experience while browsing the site and unlimited downloads.
Check out some examples of what you can get from Freepik below and hit the links below to download and test them out.
Freepik also run a couple of other pretty cool projects: Piktab is a simple, yet incredibly useful web extension that puts a new, free graphic design resource in your tab whenever you open a new one.
They also run Flaticon which is pretty much just like Freepik, but for icons. A huge search engine specifically designed for finding icons. An excellent resource for any designer.