You can find specs on all Apple products:
- By visiting EveryMac.com
- By using Mactracker (hasn't yet been updated with 2011 models)
- By entering your serial number here to find specs for your model. (Be aware that some models can use more RAM than Apple shows. Check EveryMac or MacTracker to verify.)
It says it's 8GB, is that really true?
You can replace the 2x2GB sticks with 2x4GB sticks - 1 in each slot. I had a similar question before.