It looks you mean management access
there are two ways ssh/telnet and https(via PDM)
If you need access only for address x.x.x.x (located on inside)
ssh x.x.x.x 255.255.255.255 inside
if you want restrict https access
http x.x.x.x 255.255.255.255 inside
Following links could be helpful
http://www.ciscopress.com/articles/article.asp?p=25342&rl=1
http://www.cisco.com/warp/public/110/authtopix.shtml
m.
Hope that helps rate if it does