I limit the time exposed to TV as well so they don't get too bombarded with advertisements. I let the kids have a very limited amount of time on the computer - but never without asking or me knowing about it. Some moms let their kids go wherever on the net, but it's not safe, so I have their own account set up that only I know the password to so they cannot sneak computer time. Plus security settings - I have their account on kid-settings, so no unfriendly sites are allowed, and I also tell them the rules, never give out personal information, don't go to certain sites, etc....I have 'pre-approved' sites set up that they are allowed to go to and if there's something else they want to see, then they have to ask first. No surfing the net.
My daughter is only in second grade and she is already doing reports, etc and needs to do research on the Internet....I have to realize we are in the 21st century...haha...so I set the computer up in the sunroom so I can see the screen while I am making dinner....she can do her research online and I can watch each page she is looking at while chopping veggies or washing dishes, etc. We have a set 'game time' rule, so if they choose to use their game time on the computer instead of the DS or PS3, etc, then they can....but they cannot go over the time limit (11 yr old gets 45 min/8 yr old gets 30 mins on school days, and both get one hour on weekend days). They have unlimited time for research, but we don't usually have enough time for unlimited - we are always going somewhere or eating dinner or doing other things, etc...so research doesn't last more than 30 minutes usually.
The schools actually teach them how to use the Internet as well....I would make an appointment with your child's teacher and see exactly what they are teaching them, what computer access they have, etc. My DSS said that they let him surf the net during recess, which I informed the teacher was completely unacceptable...she said that she didn't let them do that, so I think he was talking about a rain day or something - but it's our jobs as parents to set guidelines for what is appropriate and inappropriate for our children. However, I do think Internet skills will help them in the future. If I were you, I would only let my daughter go to age appropriate sites where she can read for herself...and if she can't read them, then just let her know that is her choice to be on the computer and she has to fend for herself, but it's not your job to read it for her because that is not necessary...and maybe she will take more initiative to figure it our herself. I would not waste my time trying to help her play on websites...but most sites, like Barbie or Noggin or whatever are kid-friendly and don't require much reading....also, Internet is good for eye-hand coordination, typing, etc - it would be good to get her language CDs, reading CDs, typing CDs, etc - so even if she can't get on the Internet, she can go there and just learn from pre-selected CDs you buy for her -that is super safe! And she will love them and have fun...plus learn at the same time. I remember playing Where in the World is Carmen Sandiego on the computer and it was fun but taught me critical thinking skills...and these days computer games are even better! Of course, I would still limit that time because it takes away form fresh air and exercise outside!
The companies' job is to market the best way they know how - through the kids straight to the mom - and the sad thing is, most of the time it works - so I'm glad you are taking control of the situation and hopefully you can work out something that's right for your family. Good luck!