I've been trying to get my CCNA for a while now, and finally decided to enroll in the Academy through my local university. The professor required the students to attempt the INTRO/ICND exams. For help, he recommended the website how2pass.com for practice exams.
I followed his advice, and subsequently passed both exams. I found the testing site to be VERY helpful. The practice sims were extremely similar to the exam sims.
I guess I wanted to get some feedback from others who may have used sites like how2pass.