can't find info

To whom it may concern,

Not quite sure how important being validated with W3C is but I did  
validate 5 of my pages so far for XHTML Strict.  Please help a sister  
out here, though, I notice talk on your site about html 5 and want to  
know if I am wasting my time validating for XHTML Strict?  IE makes my  
pages look different that Safari or FireFox which is a known problem  
for any code on any website. What do you recommend? I have 20 more  
pages to correct and don't want to waste time and I would rather do it  
right the first time.  Any quick response and help is appreciated.  : )

Newbie at this stuff,
God bless,
Sandy
http://muralsandfauxpainting.com