There is a great wealth of video tutorials in the old K2 Community, located here: community.getk2.org/video

Same goes for any questions that might occur while developing a site with K2. The old community and soon the new one, provide the best source to learn K2 and solve issues.

Now that v2.5 is out, we plan to gradually fill the documentation section in this site with small practical tutorials covering all aspects of using K2. I personally plan to write 5 small tuts per week.

If you are just getting started, I can only say that working with K2 is like working with default Joomla! articles, only much easier and concise.

To get started, try this:
- Install K2 in an existing site.
- In the items list, top right, hit the import button. This will import your Joomla! articles into K2. Don't worry. The original Joomla! articles are left intact. This will allow you to have some content inside for you to play around.
- After the import, you already have some articles (items in K2 lingo) and categories that form your K2 content's structure. Now start creating some menu items to the K2 categories or items.
- Experiment with the K2 category options. When you flip the switch in some parameter in a K2 category, the switch will be enforced in all items of this category, everywhere in the site (unlike Joomla! articles).
- Enrich your K2 items: add tags, a K2 item image, video, gallery, upload some attachments.
- Extend your K2 item forms: go to the "extra fields" page in the K2 backend and create some new extra fields. "Extra fields" are new form items that extend the base K2 form. And that's one of the beauties of K2. You got a solid starting form for your item and you can extend it with additional fields. Imagine wanting to add a table of data (e.g. details about a movie) inside your items. Extra fields are the way to go. Once you create a few extra fields (you'll see that K2 asks you to group them), you "attach" these extra fields to your item forms, by assigning a particular extra field group to a K2 category.
- A K2 category can only be assigned to one extra field group. An extra field group however can be shared among many categories.
- Now after you've setup your extra fields (and groups) and assigned them to one or more categories, you can start adding more content to your K2 items. When you select a category that has an extra field group assigned to it, these fields will display in the "extra fields" tab inside the K2 item edit form.
- Create more menu items to users (user pages/blogs), tags or the uber-cool "latest items by users or categories" view.

Some additional things to keep in mind:
- K2 makes proper use of its "global" parameters. These parameters will most likely be set only once from you. Browse these parameters (see the button top right in all K2 lists in the backend). If some parameter seems funky too you, hover above its name for an in-depth explanation in the form of a "tooltip".
- We have a few but very powerful modules. One you'll be using most of the times and that's "K2 Content" (mod_k2_content). This is the primary module to fetch content from anywhere in K2 in dozens of combinations. The other modules allow you to fetch comments (K2 Comments/mod_k2_content), user lists (K2 Users/mod_k2_users), the K2 tools (mod_k2_tools) module allows you display lists like archives per year/month, a drop-down of your K2 categories, a calendar, a K2 specific search box, a tag cloud and more. Finally we have the K2 User (mod_k2_user) module, which is a replacement of the Joomla! login module: you use this module to allow your users to log into (and out of) your site. When they are logged in, they see some special actions, in relation to K2 and the powerful access rights that K2 can give to specific groups of users in K2.

More soon ;)