Gymnastics workout?

I've been working about for just over 5 years now: lifting weights, cardio - jogging, rowing, hiking etc. even I'm learning to jump rope now. I've got lots of benefits from these activities but I was not able to get huge muscles.

My newest and brightest idea yet (and I have lots of ideas) is to get into gymnastics and martial arts (again). It is just that I am over 35 already and I am too weak to do even the simplest gymnastic exercise. I have access to a gym but I don't have access to a real gymnastics equipment. I don't expect to get an Olympic champion and I do not even expect to learn all and especially the more difficult and dangerous gymnastics exercises.

Keeping that in mind. Do you have any ideas how should I start working out to improve my qualities so that I'm able one day to do planches and these cool, impressive exercises that gymnasts do? My dream is to do the iron cross someday.  
Just lifting weights appears not to help me at all.

Any suggestions, links, sources or gymnastics workout routine for absolute beginners you could give me will be very helpful! Thank you in advance.

Thank you very much. I'm starting with the simplest exercises now.

http://www.eatmoveimprove.com/2010/03/the-fundamentals-of-bodyweight-strength-training/

That's the best most in-depth article I know of for your interest. Covers most every base and should give you a sense of things if it's something you're really interested in. Goodluck

i would also start with being able to do a lot of pull ups and dips which i think are fundamentals to all those skills