There are a ton of great resources out there. Here are some I use. Let me know if I am missing anything
Creative Market
Great souce for themes. I got the theme for my uncle's site here for about $30.
Dollor Photo Club
The name says it all. Get great photos for $1. Although, I always check Stocksy first since their images are free. Or I just take a photo the old fashion way.
Font Awesome
I actually use this site more for icons. Tons of icons. No need to download anything. Simple code to insert the icons onto any site. Here are a few below.
Land-book
Similer to Dribbble, but for landing pages. Great place to go to get site design ideas.
Theme Forest
If you are making a WordPress site and don't know how to make a theme, this is the place to go. Great themes for under $60. Be sure to check Creative Market, because in many cases those themes are less expensive. I got the theme for this site off Theme Forest for about $30.
Typography
Great souce for fonts.
Webtype
Great source for fonts. Might check Google Fonts first.