First, let me start by saying i tan pretty easily, because of my mediterranean background FWIW. Your skin looks a little lighter, so take that into consideration. Here's what I do:
Week 1: Two 15 minute sessions at even intervals.
(you might want to start with ten minute sessions just in case)
Week 2: Two 20 minute sessions.
Week 3: Three 20 minute sessions.
Week 4: Maintenance, two 20 minute sessions.
I continue like this for a max of six weeks, then take a minimum 2 months off. Although I do agree with Mr. X that u can just maintain with one session a week, I take some time of for safety issues. I use a bronzer (california tan for me), always wear goggles, shower after and pack on as much moisturizer as humanly possible after my shower, especially on the face. I also up my antioxidant intake. I use a moisturizer on my face daily, regardless if i tan or not. This is your skin, and it has to last you a lifetime, don't get cheap with it. Buy quality moisturizers and dont forget your antioxidants.