Figured I'd try to help explain some of the new things going on...
Let's start with the new opening page, the "dashboard". I've highlighted a few spots worth understanding. The top is the upper menu that you'll see everywhere across the site. Click once on your username to access profile settings. Notifications shows you anything you've picked to be notified about. Conversations are where you'll find private messages. The next row is the site menu, and will show you the number of unseen posts or photos. In the main display, it starts with up to 5 threads with unseen posts. Below that is general activity, posts, likes, photo uploads.
Speaking of notifications... click on that menu option and it'll show what's waiting for you. Click on the gear icon to access the items that will display there. Click on the top checkmark to mark them all as "seen" or the individual items. If you don't goto the thread or click on the checkmark, it'll be there waiting the next time you visit the site.
Moving along to the forum display... I've marked the side menu. The eye is a spot to ignore specific categories, the checkmark is "mark all as seen", next is RSS feed, then sitemap and "goto bottom of page". Over in the forum display... If you want to tidy up the view, click on the V arrow to collapse that section. If there are any unseen posts, it'll still let you know. If you want to ignore that section completely (either group or an individual section, use the menu on the right with the eye (scroll down for more on that). If you want to clear the "unseen" number for a specific section, double-click on the folder icon and it'll mark them all as "seen" (this works for specific threads as well, within the thread list).
Here is what you'll see from the "eye" menu. You can either hide a category or a specific section by un-checking it. If you use this menu, it'll also ignore them as being "recent" and not include them on the dashboard or in the "unseen" post totals. I'm not really sure why you'd want to use this on our forum, but it's there if you want.
And perhaps the feature to be most used... the post-hover menu. While looking at a thread, move your mouse over and it'll display this in the bottom right. First is the "save to quote" option, where you can select one or multiple posts to quote when you reply (scroll all the way down or up and click on the "reply" button). Next is the "report to moderator" option, where you can report spam posts, or something that gets a little out of hand. Next is "like". You won't see this on your own posts. Next is "to the top", to bounce you to the very top of the page. One option missing will be an "edit" icon before the quote icon, if you're looking at your own post.
Moving along to the gallery... the right menu has the "mark all as seen" option similar to the forum. This is great so you don't have to look at every single new image to clear that. What you're looking at are "categories" of photos, showing from all users. This will let you get your trail ride fix when you're stuck at work in February. To the far left, across from the checkmark, is a small menu "Albums, Images, New Images, Map". Club members will also see "My albums, My Images". Albums will display individual albums owned users, images shows all images, and new images shows the images you haven't marked as "seen" yet. Map will show you a google map with any image that was tagged with a location when uploaded.
I hope this makes sense and helps make the new site a little more enjoyable.