I'm not an SRNA yet, but I would honestly to advise you to think first about your personal situation, experience, comfort level, and examine what you want out of your CRNA program to start this process. There are obviously a number of programs all over the country, that are many different sizes, in many locations, costs..
For some it is important to stay locally for their family/personal situations. Others are able to relocate for the right program. I started out by printing off the list of AANA approved programs and researching the requirements, cost, size, pass rates, rankings, etc... of each (it took a long time). I then narrowed down from there. Are you hoping to achieve a MSN or Doctorate degree? There is a much smaller number of doctorate programs than MSN ones.
Another great option is to speak to CRNA's about the programs they attended. I am lucky to have friends who are now in a couple of different programs around the country, and hearing their experiences and opinions of their programs has been very helpful to me.
Lastly, don't be afraid to contact programs that seem like a good fit for you. I have had a number of conversations with admission counselors and even some department heads and CRNA program coordinators. It helped me get a great feel for how each program approaches applicants (which has also helped my decision to apply).
Its easy to get caught up in how selective programs are, whether you fit the requirements...etc, but at the end of the day, CRNA school is a huge investment of your time, money and stamina. I want to be sure the program is interested in me and cares about the hard work I have done in order to apply and prepare for their program. I have discovered some programs are very willing to reveal what you can do to be a competitive applicant while others refuse to reveal more detailed specifications. This has helped me narrow down even further.
Good luck to you! With any luck I will become a SRNA sometime this year or next, and I can offer more detailed advice about my own experience!