If you're going to be "shopping" for images for the site, I thought I would give you some links, and information to help you find the best stock possible.

When people hear information, they're likely to remember only 10% of that information three days later. However, if a relevant image is paired with that same information, people retained 65% of the information three days later.  Source

Consider images that would be welcoming to first-time site visitors. 
 

“STOCK IMAGES” aren’t all bad, but you can generally tell the pictures that are fake stock images!

In a recent study, they've found that users pay close attention to photos and other images that contain relevant information but ignore fluffy pictures used to "jazz up" Web pages. Source
 

Try to consider stock photo sites that allow their photographers to do the best job at submitting things that look REAL; using real (normal) models and typically a modern, unfiltered edge to their work.
 

COMMERCIAL STOCK IMAGE SITES

www.iStockphoto.com
great search tools, very common/typical posed shots

www.stocksy.com
more-artistic images, unique, hip, modern. This site is geared more towards striking a vibe with a particular photographer; it's much easier to browse everything a photog has shot— once you find the tone that you like

www.veer.com
(like istock; typically better quality) great search tools
 

FREE STOCK IMAGE SITES

There are several sites that offer "free" images to use commercially. Some may require attribution, but for the most part, many photographers are just giving-away their rights on their images. 

WHAT IS ATTRIBUTION?  https://creativecommons.org/licenses/by/3.0/us
Attribution is the act of giving the original author of the content credit for their work; think of attribution similar to a citation in a research paper. 

Sites like UNSPLASH are hipster-slanted; you'll find more images of guy with a dog in the woods than guy wearing a suit and shaking hands at the boardroom table.

Our (growing) list of free stock sites

Little Visuals http://littlevisuals.co/

Unsplash http://unsplash.com/

Death to the Stock Photo http://join.deathtothestockphoto.com/

New Old Stock http://nos.twnsnd.co/

Superfamous (requires attribution) http://superfamous.com/

Picjumbo http://picjumbo.com/

The Pattern Library http://thepatternlibrary.com/
 

IMAGE SPECS & TIPS

For large homepage slideshow areas, we would suggest around 5-7 images. 

IMPORTANT: 
The dimensions of the original image you upload to your site can have a big impact on how it displays. We recommend using images that are between 1500 and 2500 pixels wide.

IMAGE BEST PRACTICES (Squarespace documentation)
https://support.squarespace.com/hc/en-us/articles/206542517-Formatting-your-images-for-display-on-the-web#toc-image-best-practices
 

TIPS

• For searching on many of the commercial stock photo sites, you can narrow results based on "shape" (vertical/portrait — horizontal/landscape) and "type" (photo, illustration, video, audio). 

• For the website, we will generally always use horizontal images in photo galleries/slideshows— instead of vertical ones, but we can crop anything.

• If you join any one of the stock photo sites (which are all free to join), you can add all of your favorites to a lightbox. This makes it easier to browse and grab anything that interests you.

• When you're happy with your collection, share your lightbox with me/others via email. We can copy/paste the low-res/watermarked versions — and use these in our design comps (still without paying for them). When you're happy with the images in-place / when we're ready for high-res versions, you can just buy what's needed, and your lightbox will always be there for future projects.

• Images you love will be useful in your print publications or even to hang on your office walls; if you think you might use an image in multiple places, then initially grabbing high-resolution versions (300dpi) would be ideal. These large images can also be scaled to use on the website.