Authentic assessment is increasingly popular in educational institutions from K-12 to post-secondary. It is a way of assessing learning and therefore can be thought of like an exam. What makes it "authentic" is that the task for the students must mirror the task the students would perform in the real situation. For example, if students need to learn how to create an instructional design document, the authentic assessment would be to have them actually create this document. To make it even more authentic, the students could create the document for a real institution or situation.
Rubrics make grading and authentic assessment easier. The simplest form of a rubric has at least two columns. The left column lists the key characteristics that you, as the evaluator, are looking for on different rows. To use the above example again, one category (row) could be "professional writing style." The right column (or columns) gives the score or rating for how well the students' performances meets this category (usually a 1 to 5 scale works best). To get the total score, add up all the scores down the rows and divide by the total possible (all 5's for example). This will give you the percentage for the grade.
It is very important to spend some time creating the categories in the far left column. They should be as exhaustive as possible and not leave out any important details. Also, add to the rubric a concrete definition or description of the category. For example, the "professional writing style" category could be defined or described in this way: "Writing is free from spelling and grammatical errors and diction is appropriate for the setting." This way students have a clear understanding of how they are being evaluated.
Just as it is important to define the categories, it is equally important to define the scale. What does it mean to score a "5" on "Professional Writing Style," for example? Give examples in the rubric of what the different scores would look like in the actual assessment. If you are using a 1 to 5 scale, you may be able to get away with only defining scores 1, 3, and 5. However, it is worth the extra effort to define all scores so that students have a clear understanding of how you are rating their work.
It is always a good idea to include a "Comments" section to capture qualitative (written) data and feedback. The rating scores in the rubric make grading easier, but it is important to note how students could improve as well. Try to include a mix of positive comments. A good technique is to use a sandwich: start with positive feedback, then some constructive criticism, then finish with more positive feedback. This is less likely to make the students defensive when reading your critiques.
Well-constructed and proven rubrics can be given to students in the course for peer assessment as well. Have the students view the assignments and score them using the rubric and leaving written feedback. You can include this in the final grade score for the assignment, but it may be wise to weight peer reviews a bit lower than your own review as some peers may not be grading objectively.