You should actually READ the introduction included with Jeppesen approach plates. They include a wealth of information. You should also READ the FAR Part 91 rules for instrument flight, as well as the sections of the AIM that deal with instrument flight (including the Pilot/Controller Glossary). I cannot tell you how much this will increase your understanding of the rules and requirements of flying under IFR. Alot of students are lazy and do not do this. If you read and UNDERSTAND this information you will know more that quite a few CFIIs when you are done with your rating.
I also recommend the Instrument Oral Guide published by ASA. It is a little red book that fits nicely in your flight bag. It is one of the few books I carry around all the time. The Trevor Thom Instrument Manual also by ASA is also a very good book, much better than the Jep text.
When you are not reading the above info, Microsoft. Instrument flying can be practiced at home for free, as much as you want. I have MS2000 and it does fine. My computer will not run 2002 and although it is much cooler, 2000 does everything you need. I recommend the CH products USB yoke with the throttle, prop, and mixture controls at $100. Well worth the money. It is easy to set up so you can put your gear up and down, move the heading bug, CDI, etc. When you practice use the Mooney, 182, etc. Do not fly around in the 747 as this does you no good.
The instrument rating is the hardest rating you will get. It is also the most important. You have to do something really retarded to kill yourself VFR. Only a small mistake can seal your doom when IFR. If you work hard it will be much easier. Alot of students just show up for their lessons and never study. Don't be one of those students.