Rosemary is notoriously difficult to germinate... but I did have very good luck with it last year using this technique from
http://www.seedsite.eu/article (note that your container should be covered after planting the seeds, to retain the moisture; and I used a very light sprinkling of dry vermiculite to barely cover the rosemary seeds, then used a spray bottle to slightly moisten it. Rosemary also likes a warm temperature for germination, between 75 and 85 degrees F): "Fill half of the preparation container with dry vermiculite and pour water over it until just covered. Then immediately pour it in the sieve, so that the vermiculite doesn’t get too wet. It’s very important to pour it into the sieve promptly after watering; this will ensure the perfect moisture level for sowing the seeds. Gently shake the sieve a few times to get rid of the extra water. Now it’s ready to use.
"Now you can begin to fill containers with your pre-moistened vermiculite. Prepare as many containers as you’ll sow that day.
Using a large spoon or ladle, begin filling the containers. The layer must be between one and four inches high, depending on the kind and size of the seeds you’re sowing. One inch will do for very small seeds that need light to germinate; while four inches might occasionally be used for very large seeds. Gently press the layer with the bottom of another container to settle the vermiculite. Once the desired depth has been attained, it’s time to sow the seeds!"
