Mistarose,
My suggestions are plain and simple:
1.) FIRST AND FOREMOST!!! Have a ball with this one. You will learn A LOT durring this process. Not only will you learn more about the nit and the grit of the basics of your roots, but you will learn more about yourself. Life lessons that will carry you through your career.
2.) Study before and after lessons - the more you see the material, the easier it is to articulate.
3.) Practice aloud at home. I know that sounds kind of dorky, but that is one of the main things you have to get used to.
4.) Make your lesson plans in advance. Nothing sucks more than to just 'wing it.' You will be amazed as to how difficult it is, to teach someone.
5.) ALWAYS have in the back of your mind "what was this like for me at 0 hrs, 10 hrs, 15 hrs...and so on. That really kicked my but, because I am anal and articulate...but you just have to remember, 'what was it like for me at -- hours?' Try not to use big words, or fancy accronyms - make everything as simple as possible - like you are talking to a 5 yr old...
6.) Everything comes back to your preparation - your instructor will be able to tell if you did your HW. Now, he/she will understand where you are coming from if you stumble through, because believe me...everyone does, so DON'T GET DISCOURAGED!!! This is something that everybody goes through. Your CFI is probably the hardest Instructor Certification to get. - Just because you aren't "in the know" for some of the stuff. (ie. first checkride with an FAA inspector - which isn't as bad as everyone may tell you...so don't make prejudices until you experience it for yourself - go into your flight test with a WIDE OPEN mind)
Now as for the money issue, I am sure that you can figure it out. The more prepared you are, the less money it will take in the long run. I did my CFI Part 61 so what I did was purchase a Block Time of 10 hrs in a 172RG, and 20 hrs with my instructor. It took me about a month and 1/2 to get the two writtens done, my lesson plans done, the flight and ground training done. About 10 hours of my 'dual' was on the ground, just so I could teach all of my lesson plans. A lot of my airport buddies gave me crap for going through each and every one, but it made my checkride that much more easier. I was ready for anything he wanted me to teach---I ended up teaching 8's on Pylons...my favorite...NOT!
I am sorry for going on and on. Just wanted to pass on some secrets to success. If you have anything further to ask, don't hesitate. I am sure others will chime in and help ease some anxiety. Good luck with your COMM checkride, and CFI as well.
D