This has been asked quite a lot of times by newbies that how to start learning Exchange Server.
I would say MsExchange.org is the most tasty and crispy site for any Exchange hungry learner, Exchange Server TechNet Library is properly managed and untreated food made available at, by Microsoft restaurant to maintain the quality under healthy support boundaries and MSExchangeTeam blog serves the desserts at last. Also you can find various tips and tricks at the blogs of various MVPs and Subject Metter Experts in terms of snacks… :)
The best way to learn things are, do the practice or get involved in some kind of implementation and configuration assignments in your job. But it is rare to get such kind of chance in the beginning of the career so what do you in that case? The best option is start learning theory and construct a clear foundation. Anyone of the book can guide you step by step, but again caveats come, like many of us don’t get enough time or don’t be in good mood to learn the theoretical portion after completion our day job and social responsibilities. In that case I would try to find out certain multimedia or video tutorial to gain knowledge in entertaining way and some of them demonstrate how to do that step by step practical simultaneously. You may find many video tutorials in the market like CBT Nuggets, TrainSignals, Winstructor etc but definitely people will search for the costless material initially so let me list out some of the resources here…
Multimedia aided training material:
Next step towards gaining more confidence, you need to configure things by your own hands so how do you achieve this? I would recommend to build your own virtual lab with help of virtualization software like MS Virtual Server, Virtual PC, Hyper-V or VMWare. Create couple of VM instances, install and configure Exchange Server settings and see how it reacts in various scenarios. Microsoft also provides pre-configured VHD files to evaluate Exchange Server if you don’t want to build environment from scratch. But what if you don’t have enough hardware resources to build your virtual environment? Well, here is the deal. Microsoft provides bunch of Virtual Labs for Exchange Servers, you need to just have reliable and high-speed internet connection.
Now, how to keep the things in mind for long term? As I said, best way is to do practically and next thing is, keep notes of certain points which remind you quickly in future.
When you are trying to get knowledge yourselves so what do you do if you stuck up with questions or anything which start confusing you but you can’t find any way to get out of complication. Of course search engines are your friends but still you are not clear at the base then there are many Exchange Server experts sitting across the world and many of them are ready to help Exchange server community, you have to just log in into the ring of their perimeters. You can find various forums where you can ask your questions and queries which are bothering you.
Here are list of the major forums and newsgroups but wait, follow some of the best practices while posting queries on the forums/newsgroups which helps to you as well as to savior also who are trying there to help you. Basic best practices are, to post the question in proper category, write a short and sweet subject/title so relevant experts of that area will grab their call swiftly. Also see couple of links here, How to ask a question and The Psychology of a TechNet Forum Thread.
At later stage I would certainly look for in-depth or very advance level material for real world implementation and troubleshooting awareness. Couple of classical book examples are here.
Hope this helps you to jump into ocean of knowledge and Good Luck!