hi all I'm thinking about doing a web site to promote my work and get some extra income, When doing the web site should I worry about all the formats from pc to mac and now a days tablets, is there anyone system where it looks the best on all ways at looking at the website, Thanks in advance
Operating system is not really important... the issue mostly arises with how different browsers interpret code and how the website is displayed at different resolutions/screen sizes. Browsers these days are more standardized than in the past, so that is not really so much of a problem as it used to be, but still crops up from time to time. The big issue today is compatibility with mobile (smartphones+tablets). Sites that can change their design dynamically to fit mobile browsers are known as "responsive".
Since you don't seem to have much experience designing websites, I would recommend contracting a designer or using a website like Zenfolio, Smugmug or SquareSpace where most of the work of compatibility with different browsers and screen sizes is done for you. You may also find some luck with Wordpress, which is a blogging software that offers a lot of "responsive" templates where all you have to do is load the images into a pre-designed page.
+1 on the flash. Nothing says "irrelevant" faster than a website full of flash that will not play on an iOS device. About a third of my website hits are mobile and almost 90% of those hits are from iOS devices.
