Please Review and Suggest for the Layouts - XHTML/CSS Validated or Simple HTML

[ecomindia]

Hi!

I have just launched few of my websites whose backend is a common CMS / Database enabled written purely in ASP / SQL+Access.

Now , as the end product is ready, I am pretty confused whether to make the design XHTML/CSS validated or keep doing the layout in Classic HTML.

If you see, the current layout of the design (is in HTML)
Ex -http://hotelinus.com/index.asp

I have been revamping it into XHTML/CSS (because of which few links are still not working) in http://hotelinus.com/html/index.asp

Is there any benefit going ahead with XHTML/CSS (I see all big sites moving to this technology!). Also, I am new , so validation is taking good time ;-)

Please suggest, which will be a better design
1) For End users
2) For SEO

If any suggestions or changes are there, please do guide.

Every single suggestion can make a difference to my site.

[ecomindia]

Any inputs please?