VarietyI try to give the students a wide variety of resources. There are so many to choose from: videos, text, interactive webpages, worked examples, tutorials, slideshows, online quizzes, online textbooks... it would be impossible to list one of each kind for each learning goal.
Instead, I try and make sure I list at least 3 or 4 types of resource with each goal. At the bare minimum, the "Learn It" list always includes videos, our textbook, and an in-class mini-lecture when appropriate, while the "Practice It" list always includes various worksheets and our textbook. From there, I vary it up depending on what I can find.
I want to make sure many learning styles are addressed, as well as the various access points - not all of our students have internet access at home, so paper copies of worksheets and the textbook are still a necessity (and some prefer them over online resources anyway!).
AudienceI often try to match the vocabulary level of the resource with that of my students. Whether it's a video or text on a page, I'm always looking for material between the lines of "too easy/immature/childish" and "too hard/mature/complex."
In addition to the vocabulary used, I look at the layout of the page, tone of voice in the video or tutorial, and level of math presented. What will appeal to the students? What will engage them? Will this be a site they are willing to return to in order to review or learn something new?
Though they don't often find new resources on their own, when the students do find something they like I ask that they show me so that I can add it to the list.
Complete PackageThere are a great many online worksheets for every math topic under the sun. In addition to finding ones that are at the right level for my students and have the appropriate number of practice questions (greater than 4 but less than, say, 20, which some students would find daunting just by looking at the page), I only ever include ones with an answer key.
The whole point of this style of learning is that the students can identify a way to learn, and a way to practice, on their own. In my mind, having the answers at the ready so they can see that they've got it is a necessity. In a selfish sense, too, it saves me having to assess random worksheets to see if the students got the right answer. Instead, the students only come to me when they know they've made a mistake, but they can't find where they're going wrong.
Interactive quizzes which provide immediate feedback (and even hints sometimes) are always included when I can find them.
When Nothing Else Fits...Even with the abundance of resources on the world wide web, some students still can't find what works best for them. One has declared that she "can't learn from the internet;" one told me that he prefers just a worked example (no preamble or instructional jazz) to study and work through on his own.
For students like the former, I make sure to touch base with them in class, answer questions, offer mini-lectures or work through review with them on the white boards. For students like the latter, I create one-page worked examples (see picture above). Perhaps in time I'll make my own instructional videos, too, for when I can't find anything suitable online.