Since your plane is an ARF, you may find a few people over in the ARF forum who've assembled and flown it. I believe Nitro Planes also has a support forum there. I've never owned one of their planes and never dealt with them so I can't say for sure how they are to deal with.

One thing that I really would recommend is sticking to the more mainstream manufacturers such as Great Planes, Hangar 9, Sig, Goldberg, etc. when you are just starting out. They tend to have better instructions, quality control and technical support. Once you have a few planes under your belt, you'll be better equipped to deal with the issues often found on the cheaper ARF's and kits. I'd also consider something else besides an Extra 300 for your 2nd plane. Look at something like a Sig 4-Star or similar. RCKen put together a good list of trainers and second planes in the kit forum. I'm not being critical, I just don't want to see anyone make the types of mistakes I have in the past.