i guess its not that important because i've so far , not found any1 discussing abt it.
Do i just need a cable for my rcb6i or ill have to buy the simulator software as well?

Yes its a good practice session and will learn basic acro  with out any damage

Its very very important . What if you buy 1000$ Model and crash within 2 sec ? You will feel that once you try a Simulator .
You will need cable as well as The USB dongle .

And obviously ... Afford to crash n number of times...
Not a good habit though

Yes it is necessary to have atleast a few flying hours on simulator. It is so because you never know how your plane is going to respond although it has been made upto the mark... Simulator helps to have a better control on aircraft and then later on you could even practice various other maneuvers and stunts without a loss.
You could use any of the simulators available on different stores. Do not forget to check whether it has a combination for the jack in your TX.
Check on www.quadkopters.com
This is costing for 675/- very good. contains all the cables and software too. Almost all the sims available give the software too.