I have found the six small meals a day plus snacks (I think recommended in the What to Expect book) has worked really well in controlling my nausea and stopping me getting hungry (which always leads up to being/feeling really sick). My pattern today for example will be something like:
4am - glass of milk (not strictly a meal but I woke up hungry and feeling sick and it really helps in filling the stomach)
7.30am - another glass of milk and a large handful of almonds (needing protein!)
9.00am - half a papaya, wholemeal toast with Nutella, rooibos tea with milk
12pm - small bowl of cream of tomato soup with half a tin of butter beans
2pm - two hard boiled eggs with tomatoes and wholemeal melba toast, lemonade
4pm - some frozen mango, lots of water
6.30pm - small plate of chicken breast with three veg
9.00pm - big bowl of popcorn and probably some dried fruit, some herb tea
I go to bed at 10pm so I feel like I am eating constantly but I feel so much better since I started eating little and (very) often.
I find toasted cheese sandwiches go down really well when I absolutely can't face anything, and dried fruit (esp mango) is great on keeping off the nausea on the go.
HTH and good luck!