Hi,
Congratulations on recognizing that you aren't the best judge of how useable your own site is to visitors. Many site owners fail to realize that we are totally biased by our own pre-conceived understanding of what we intended when we build the site. Here are a few notes to get you started:
Make the purpose of your site obvious:
One of the first things I like to ask myself is what is the purpose of my website? Is that purpose obvious to new visitors? In your case, I think you are selling a variety of certification classes related to ecologically friendly occupations. Do I have that right? Honestly, it took me a bit of time to even formulate that guess. Is their are way you could make your purpose more obvious?
You have a large carousel at the top of your site. Most evidence suggests that Carousels are really bad for usability. In your case, the strongest message in each panel doesn't help me understand what you do:
Get into Solar - Cool are you selling Solar power to me?
Become an Energy Auditor - Nice are you hiring?
Join the Clean Energy Workforce - Great, your going to help me find a job?
None of those 3 headlines, tell me that you offer classes. Much less, why I'd want the class. Are you expecting that I already have a green energy job, and I need a class to get a raise? Get a new job? Get my first job? Do I need the classes to get some special accreditation that I need to keep or get a job?
What about these classes... Do you teach them yourself? Are you an aggregator of other peoples classes? If they are your classes, what are you qualifications? What accreditation do you have to teach the classes? How will my life be better if I take them? Which one should I take?
All the titles in your top Nav, and the menu items that drop down are not self-explanatory. What would a new visitor expect to see under "Corporate Solutions"? What the heck is a BPI Building Analyst + Envelope?
It seems like you site is tailored to people that have a lot of familiarity with your industry and understand your business before they ever get to your site. Is that your intention?
Some great tools to judge how useable your site is:
Do a FiveSecond test on your site using http://www.fivesecondtest.com/ or http://verifyapp.com/. Recruit some strangers to perform the test. You'll probably find that the value proposition of your site is not clear enough to come through in 5 seconds.
**Make your conversion goal more obvious. **
Exactly what is it you want me to do on your site? I'm assuming it's signing up for a class, but the Select a City button (for the find a class near you) is the closest thing to a call to action you have on the page, and it's very close to the bottom of the page. I may never scroll that far down your site.
Be clear about who your audience is.
It feels like your site caters to people that already know they need to take a class, and already know that's what you do. If so, you may be fine. But if people are finding your site who don't know they need a class, or don't know that's what you offer, then you might want to rethink your messaging.
Is your bounce rate high (and your engagement low) because you are getting the right audience and they aren't getting the right message? Or because you are getting a different audience than you expect? You have Google Analytics installed on your site, so go to the traffic sources report, and look at the summary page. Is your traffic coming from PPC, Referrals Search, or Direct? If it's Search or Paid, what are the keywords that are sending people to your site. Do the keywords match who you think your audience is? If it's referrals what sites are sending people to you, and do they match who you think your audience is?
Is it easy for visitors to convert?
Assuming you are getting the right traffic, and (unlike me) the right traffic can easily figure out what you do and why they need it. Then the next question is can those visitors easily do what you want? This is where usertesting.com is a terrific tool. Write a few of tasks that you think are the most common things you want visitors to do on your site. Pick your top 3 and make sure they shouldn't take more than about 10 minutes for a user to complete. Spend $200 to get 5 tests. $50 of that goes to the test subjects, and $150 is very reasonable for what you get.
Whats the videos and prepared to be horrified by how non-obvious things are to average users (that will be totally obvious to you).
Get a free trial account from http://www.clicktale.com/ or http://www.crazyegg.com/ and record some user sessions. Are people clicking where you expect?
Eventually there are tactics like A/B Testing, you'll want to include in your bag of tricks eventually. But for now I'd stay more general.
That should get you started. You might consider investing in a book, and if so I'd go for something general like:
http://www.amazon.com/Conversion-Optimization-Converting-Prospects-Customers/dp/1449377564/ref=sr_1_1?ie=UTF8 <-- good blend of being generally enough and relatively recent.
http://www.amazon.com/You-Should-Test-That-Optimization/dp/1118301307/ref=sr_1_1?s=books&ie=UTF8&qid=1363235488&sr=1-1 <-- the most recent title, but a bit too testing specific for you right now.
http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/0321344758/ref=sr_1_1?s=books&ie=UTF8&qid=1363235512&sr=1-1 <--- a bit old, but the best/broadest overview on usability.
That should be plenty to get you started. You've executed a lot of tactics on your site very well, so I'm guessing once you get a little bit of usability theory under your belt you're going to be in great shape! Good luck!
-Jason "Retailgeek" Goldberg