Hi Sylmac,
Thankyou so very much for such great information. I had a look at the link you provided on tone-mapping and found it very helpful. I have attempted to create one HDR image ... but am not happy with it ... so won't be 'sharing' it at this stage!
I used a tripod, took 3 photos - all at different exposures - night time shot of the Sydney Harbour Bridge. Each of the individual photos is nice and sharp, but the final HDR image seems blurry .... I need more time to experiment - but at least I now know the steps, thanks to you.
Lenita