One of my HTC Desire HD's was rooted and stock 2.3.5 was added to remove the bloatware from the network.
Its not too hard but a mess on sometimes, the one i have now is a works one so i can't mess with it.
Now my iPhone 4s is a completely different story lol.
Just make sure you back up your stuff first, the good thing about android rooting is you can add a back up back on and not remove the root unlike IOS.
Research it first.