"couldnt understand topic 'Index Tuning Wizard' in BOL"
Me neither, the first time I read it!
You use SQL Profiler to record all the queries on your system over a "representative" period of use.
Then at some convenient time (e.g. when the system is quiet!) you process that Profile Log with Index Tuner. There are various settings you can select - such as how "complex" you want the Wizard to consider making your indexes, and whether you are happy that it considers dripping existing indexes.
It churs away (probably for HOURS!! on a log from a reasonably busy system) and then advises on Indexes to create, plus it provides a bunch of reports on why/how/etc.
You then decide which indexes you would like to make (or you let Index Wizard just create them for you, but I reckon that's way too scary!)