Recently I have been getting to grips with the specific details of WCF - Windows Communication Foundation (.NET 3.0) as it is a very powerful alternative to distributed computing. Although WCF has been released for sometime, only now with the advent of Visual Studio .NET 2008 can the real power begin and make integration and WCF service development easy.
WCF is a massive subject and you will find some books over-complicate or delve in too deep to begin with which makes learning difficult.
A book I am fond of is Pro WCF by Apress which I blogged out a while ago here.
Of course there are lots of WCF samples, whitepapers on Microsoft's WinFx site here.
You will find with Microsoft's site above, most of the code samples are pre VS 2008 so target VS 2005 with the WCF orcas add-in.
I have recently found a set of 15 web casts from Michele Bustamante a Chief Architect of IDesign and a Microsoft Regional Director and a Microsoft Connected Systems MVP.
You can get these web casts from here:
Part 1 SOA Concepts and an introduction to WCF
Part 2 Contracts
Part 3 Contract Versioning
Part 4 Exceptions & Faults
Part 5 Bindings
Part 6 Hosting
Part 7 Messaging Patterns
Part 8 Instancing Modes
Part 9 Concurrency, Throughput and Throttling
Part 10 Security Fundamentals
Part 11 Federated Security
Part 12 Reliable Messaging
Part 13 Transactions
Part 14 Message Queuing
Part 15 Extensibility
You can get the source code for these web casts here.
See here for an example of consuming a WCF service via a Windows Mobile device.