I had the same issue you did. I still went tanning, jsut be careful. You will get a little red.
I started at 40mg and went up to 80mg day. Worked really well. Use Neutrogen "OIL FREE" face lotion, Purpose face soap, Eucerin body lotion. Trust me, that is the best combo. Also, you lips are going to be so dry you won't be able to handle it. Put chap stick with SPF on them when you go tanning or are in the sun and I suggest you buy some Cortibalm from www.cortibalm.com That stuff saved my life when I was on Accutane. I even always made sure I had an extra tube because I couldn't go a day without it.
I'd love to hear how it goes, as I'm haveing a hell of a time keeping my lips from drying out with 30mgs a day about two weeks so far, but I love the way my skin on my back is now.