I understand your eagerness to learn. I myself have just begun my iaido journey (started in April). Having done what I have, I would not endeavour to learn iaido on my own. There are so many little things that are pointed out to me that I wouldn't realize otherwise. If you decide to train on your own, I wish you the best of luck.
I find the time I spend training fun, peaceful, frustrating and a buch of other things all mixed in.
Just keep a few things in mind:
1.) You may be picking up some mistakes that will take quite some time to unlearn
2.) Remember there are several styles and each one does things a little differently (even the way they draw, cut and return the sword)
3.) You will be missing out on some of the not so noticable aspects of iaido.
4.) As mentioned in a previous post, use an iaido or even a bokken with a saya. You don't want to keep drawing incorrectly with a live blade and split your saya! My sensei has told me that he has actually seen someone cut their thumb this way.
A few things you could do if you want:
1.) Strength train your wrists
2.) Read up about the history of iaido (if you know the style of the dojo you want to train at, then focus on that)
3.) Familiarize yourself with the names of the kata in that dojo & try to find video clips online for future reference
4.) Go watch a few classes at this dojo
5.) Talk with the sensei
6.) Find out what is required to start training there (do you need a iai obi, a hakama, bokken or iaido when you start?) You can then begin to purchase a few of these. I would suggest not buying an iaido until you start though because they are particular about what you need. Might want to enquire about the color hakama and iai obi you will need (esp if they award rank in that dojo)