Same as all the others really. Place in a seed tray or small pot (just a few, imagine little plants growing how much room they will need) .
Compost in the pot, then sprinkle the seeds on top then a fine covering of compost on top of them then water.
Place on a windowsill or somewhere bright. 7-21 days you should have some poking through.
when large enogh to handle, prick out and pot on into a large pot and grow outside.

If you sow a few every other week, you will have salad leaves right up till the end of autumn.