First, welcome to the community, second, holy #*&*, what a crap agency to do that to you. Really sorry it hear it, people like that piss me right off.
Quote from: jimmadsen at Jun 12, 2015, 09:18 AM
The area where I get lost is in trying to edit the layout and design. For example, on our site (www.ACGMaterials.com) I need to add a "Products" tab next to our "Solutions" tab that would have the same shelf menu display.
This is exactly the kind of thing that will make a non-developer pull their hair out, because there are literally hundreds of ways your developer could have set this up for you and it may or may not be a super simple change. Often, design/structure changes, even minor ones, will require at least minor changes to your site's nuts and bolts (templates, chunks, HTML/CSS, etc.)
I can tell from the tone of your post that this is precisely the kind of stuff you don't want to get involved with, and frankly, it's a bit of a rabbit hole if you don't have any background in it. As much as I'd like to encourage you to dig in and learn, you're absolutely right to fear it taking over your time and killing your productivity.
I'd love to help you out myself but we're constantly overbooked as it is.
I understand the core MODX team offers support:
http://modx.com/support-and-services/#work-with-us
There's also a directory of providers here:
http://modx.com/professionals/
Don't be affraid to work with someone internationally. The MODX community in Europe is really strong.