Good websites for 1st graders in an inner city school

Hi!  I'm new to the DEN and I am looking for other first grade
teachers that teach in a Title I school.  My challenge is I only have 4
computers in the classroom, one of which is an old Mac that won't run
alot of programs that are available on the internet.  My next issue is
that I use the computers in learning centers while I'm working with
small groups and for children who finish work early - so I need sites
that kids can really use without a lot of my guidance.  Since most of them do not have access to computers at home their computer knowledge is not very high but I've been working hard to remedy that with lots of trips to computer lab.  Starfall is
great but they are starting to get bored with that.  We are also using
Stanford Math as an intervention for struggling students in math but I need and
want more. What internet resources are other first grade teachers using
that children can actually USE and don't require a lot of reading on
the part of the child to figure out what to do? 

Any ideas?

Karen