Image SIze Question, Do I need to resize it for my website? Options

[alia828]

I have a fairly large photo I have turned into an imagemap...My question is, should I resize the image to the normal browser window size? What if somebody has a large monitor , I would like for them to be able to see a large version of the photo if possible. If I Should resize, should I do this in the html or in photoshop? Ok, one more...I tried resizing it to normal window size at one point and when I saved it and reopened it, the photo looked very grainy, why?...any help is Greatly appreciated!! thanks!

[venti-anemoi]

Quick question - when you save your image file, are you using save as or save for web? I've noticed that if you use save as and make it .jpeg or .gif, the saved version tends to be a lot grainier than how it looks in photoshop. But if you use save for web, that shouldn't be a problem.

The smallest sized screen resolution most people have is usually 800*600 pixels, and people get annoyed if they have to scroll two ways (vertically and horizontally) so I normally make the image less than 780px or 770px (because the scrollbar takes up part of the screen). But like MissHygeinic said, if you're intentionally making it a horizontal-scrolling layout, the width can go beyond 800px and it's the height you have to think about; I'd say no more than 400px high.