Its better to self-study rather than joining a course to attend CCNA exam. You will get indepth knowledge only thro self study.
Start with the following books for basic understanding of networking.
1) Data communication networking by Ferozan
2) TCP/IP by Dougles E. Comer. ( Just first 6 chapters are enough)
Then go through anyone of the following study materials
1) CCNA preparation guide by Wendell Odom - Cisco Press Publication (recommended)
2) CCNA guide by Todd lamelle - Sybex Publication - (If your intension is to just pass the CCNA exam rather than getting good knowledge - read this book alone)
Go through the Testking materials for atleast 10 days before writing the exam.
EXAM DATE : There is no specified date for the exam. If you feel confident enough to fix it , just go to the Prometric Test center and register a date for the exam according to your convenience. In India it costs around 7000 Rs ( during the year 2005 , I am not sure abt the fee now).
FOR MTECHs :CCNA is just an introduction to networks. IT is useful for network protocol stack developers.It is not that essential for MTECHs in communication engineering. If u have CCNA , then it may help u in your work sometimes. For MTECHs in communication options are many. You may get into algorithm development , communication architecture implementation, coding theory . In these cases Having CCNA won't count.