Hi - can someone advise what should be done with a new battery before I install? The HD shop said a quick blast on a charger should do it - maybe for a couple of hours... but then someone told me today at least 24 hrs on a full charger is needed?

Without doubt, if you want your battery to have a long service life, a 12-16 hour charge time, at the lowest possible rate, will be your friend.
You could charge it for an hour or two, and throw it in the bike, and it will appear to work well, but it is unlikely to last as long(ultimately).
Batteries hate quick blasts. They like long slow trickle feeds, for hours on end. ESPECIALLY WHEN NEW.
Whoever told you 24 hours is on the right track, and is helping you.

Many thanks DynaRider!! Will get it charged! Now my next problem is....

shit i have just bought a new battery and the stealer never told me to charge it maybe ill have to take it out and charge it overnight i just put it in my bike and went for about a 60k ride should i take it out to charge it properly

Yes, I would.
But bear in mind, it may have been well charged by the dealer.
A friend of mine just bought a new battery from a HD dealer, and as he had asked me about it first, he enquired as to what procedure they had followed.
They had in fact charged it overnight for him. It was ready to go.

ok thanks dynarider ill take it out tonight and charge it overnight and put it back in the morning asome charge will be better than no charge and shouldnt hurt the battery

ok coolies thanks obiwan i am currently looking at such a device on ebay at the mom its a floater charger as you state so ill def purchase one, just a question does having the extra leads connected to terminals once charging have any affect on the alarm and wiring etc?

+2 for the battery fighter, battery 4yrs old and still like new..................