You only weigh daily if the pig is sick. Otherwise once a week is fine. This is because guinea pigs are very good at hiding illnesses, and so often the first and sometimes only sign of illness is weight loss. Draw up a table on excel/word/other program and record their weights.
There is no right weight. Each pig is different. Lily, who is about 11 months old weighs a tiny 860g compared to Rosie, who is 6 months old and weighs 1006g. My biggest is Toffee who weighs in at 1030gs and is 9 months old, and Buttercup who is 1 in 6 days is about the same weight as Rosie. I dont think Buttercup and Lily will get much bigger, but Rosie and Toffee havent finished growing yet!
Remember to weigh at the same time (afternoon, morning, night etc) each week.
Guinea Lynx :: Weigh Weekly!