We work with a lot of small, growing partner organizations. Besides internal IT, the next tech that everyone needs is a web site with a few basics like a way to allow supporters to subscribe to a newsletter, and a way to take online donations.
You can do it yourself with a site like SquareSpace, but now you need to invest the time in understanding how it works, doing your own design and creation, and of course ongoing maintenance.
For a larger organization like mine, we hired a dedicated design/development firm and created a bespoke site. But that is out of the reach of most smaller orgs. For those, I recommend LiveImpact.
LiveImpact is a integrated suite of tools designed specifically for the needs of non-profits. It was started by Ravi Gauba, a Silicon Valley veteran who wanted to help solve a critical capacity-building need for the non-profits he and his friends and colleagues were supporting. His family is passionate about cheetahs, which is how our partner Cheetah Conservation Botswana ended up using them for their redesigned site. I think it turned out really well. Also be sure to check it out on your phone and tablet.
For a basic template-based web site (which is responsive / mobile-friendly), they will do 2 weeks of design and development work for about $2000, and run the site for $600/year. This is a pretty great deal compared to other options. They also have mailing list functionality, and will take online donations for a 2.2% fee.*
LiveImpact provides other services, too, so it is a vendor that will grow with your organization. I highly recommend you check them out.
* Numbers are representative. They might be different for different orgs. Please talk to them directly to get an accurate quote.