everyone is always afraid of losing muscle,and for good reason, we work so hard for it. honestly though, you can lose a good amount of your fat without worry. if you're at 18%, you can cut out some carbs and fats and still have plenty of nutrients left in your diet to support your muscle. if you want to cut and get lean, i would suggest you slowly take the carbs and fats down. im not sure what you're doing for cardio, but i would suggest the step mill or the treadmill, doing slow steady state cardio. not much. i would start with 30 min and add a little every 3 wks. i would work on losing a few % body fat before you add in AAS. it's going to take you awhile, if you want to do this right. focus on losing no more than 2 lbs per wk. at first, you'll see a decent weight drop when you clean your diet up. water weight will fall off of you. you may lose 10-15 lbs in the first wk or two, thats ok. but after that, it should slow. if it keeps going too fast, add more clean food back in. chances are, if you're getting enough clean carbs, proteins and fats, you can reach a state of staying close to the same weight while getting leaner and leaner. thats when you have your diet nailed!! so don't just rely on the scale, use the mirror and weekly pics taken from the same angle, in the same light. on or off gear, your muscle will look more flat while dieting. this isnt muscle loss. this is just part of the process. i've knowna lot of guys with higher BF% that start getting scared when they see this happening. so be aware going in. you may look flat at times and you may not feel the same pump. once you reach 12%, it would be a much better time to introduce AAS. here is what i would suggest for a guy at your level...and yes, i'm going to talk about injectables. they are much safer for your body than orals. you only want to use an oral for a shorter time because they are toxic. you cant run one long enough to do the full job of cutting. not to mention, you need test in your body, or you will get shut down and feel awful. you mentioned the word "education". good call. education here is key to keep you healthy and safe. there are many sites online that give you photo walk throughs on where to inject. there are articles written about proper thechnique. i would go to nap's message board, juicedmuscle.com . there is a ton of good info there. here is an article they have about this topic  http://juicedmuscle.com/showthread.php?49-A-Guide-to-Safe-Injection-Technique

so here is what i would do.

wks 1-12

test e 350-500mg EW, split into 2 weekly injections on monday and thursday

adex .5mg EOD

wks 6-12

either oral winny at 40mg ED or geneza's MHN at 20mg ED

either of these orals will help to harden you up at the end of your cycle to help show off your new, sculpted physique. 

PCT begins 2 wks after last injection

in addition to this, i would also consider using a fat burner when you reach the cycle phase. clen is good, you can start at 40mcg ED and add 20mcg every 2 wks, through the cycle, going no higher than 120mcg. you'll see that people outline different programs for clen, but this works very well. someone's theroy doenst mean shit against results and i've gotten as lean as i believe a human can get, using clen in this fashion. other options would include using ECA, which also works well for fat loss but has more highs and lows through the day. its half life is very short and must be taken 2-3 times a day. personally, i feel that it breaks my body down, not in a good way. i only use it for short periods, if ever