Chain (ch) -- Yarn over and draw through previous loop. (To begin a chain, make a slipknot and place on hook.)
Slip Stitch (sl st) -- Insert hook in stitch, yarn over and draw loop through stitch and loop on hook.
Single Crochet (sc) -- Insert hook in stitch, yarn over and pull up loop (2 loops on hook), yarn over and draw through remaining 2 loops.
Double Crochet (dc) -- Yarn over, insert hook in stitch, yarn over and pull up loop (3 loops on hook), yarn over and draw through 2 loops, yarn over and draw through remaining 2 loops.
Half Double Crochet (hdc) -- Yarn over, insert hook in stitch, yarn over and pull up loop (3 loops on hook), yarn over and draw through remaining 3 loops.
Triple Crochet (tr) -- Yarn over twice, insert hook in stitch, yarn over and pull up loop (4 loops on hook), yarn over and draw through 2 loops, yarn over and draw through 2 loops, yarn over and draw through remaining 2 loops.
Yarn over (yo) -- wrap the yarn from back to front around the hook.
Slipknot -- The initial loop to begin a crocheted item; best visualized. Make a small loop about 4" from end of yarn, pass the end behind the loop (looks like a circle with slash through it), insert the hook to pick up the "slash" and tighten both ends of yarn around the hook.
Keep going! See what happens when you keep adding more rows or rounds.