Hi all,
I have been using this tool for the past 1.5 years and I learnt it in my college during my free hours (ofcourse later I made sometime free for it particularly) and was designing posters and certificates and brocures for all my college events and symposiums. At first, it looked hard for me to use it bcos of many options avaliable and lot of dropdown menu options. Actually at one point I never thought I will learn this software. But, when I started learning it slowly, I felt easy day by day and the help files provided are really great. I am very sure that u dont need a book to learn photoshop.
I also tried Ulead photoimpact and it is also good bcos of the lot of templates and readymade gallaries it gives... but the tools provided in it are not really powerful when compared with photoshop. For a designer who want to get out to the screen what he has in his mind, the tools are most important than the readymade gallaries avaliable. These readymade stuff can enhance the design but cannot be the base of a design. So, u can have also photoimpact as additional tool in ur design kit!
Photoshop 7 provides additional tools and filters even. The most remarkable is the patch tool and the healing brush tool. U can do wonders with them actually...