Here's a list of foods/drinks that should be avoided, as well as foods that you can try to keep down. Remember to never start or stop anything without speaking to your doctor first though.
Things to avoid would be some of the follow:
Greasy, fat foods.
Try to eat small meals throughout the day. Avoid large amounts at one time.
Take small breaks in-between eating and try to eat slowly.
Caffeine (such as soda and tea) can sometimes make nausea/vomiting worse. Tea may help to soothe an irritated/upset stomach. Make sure the tea is safe for pregnancy, such as green and black tea.
Things that might help:
Crackers in the morning could help to stave off nausea/vomiting. Try to eat them before getting out of bed if possible.
Sleep propped up slightly in bed.
To reduce pressure on your stomach, lying on your left side helps more than lying on your right--I spent many a nights lying like this and it works well.
Foods such as bagels, pretzels, rice, pasta, toast, rolls, potatoes, can usually be handled well.
Try to eat as much protein as possible--Chicken, eggs, nuts (almonds, peanuts, cashews), steak, peanut butter, etc.
Lemon and water can help with nausea, or lemon alone might help.
Ginger might also help queasiness and may settle the stomach.
Spicy foods can also cause nausea and vomiting and may want to be avoided.
Some women find the sea-bands can provide comfort from vomiting and nausea.
Emetrol is also safe to take while pregnant and might help if you need quick relief.
You can also take a mix of B6 and unisom to provide relief as well. Speak to your doctor before starting this. They might have you try a specific dosing/amount.
DON'T feel bad though if the only thing you can eat at first is junk though. What's important is that baby and you get some form of nourishment. Never hesitate to contact a dietician and express your concerns to them as well. Sometimes the only things that really help are anti-nausea medicines, and if that's a route you have to choose then it has to be done. I was on Phenergan for 7 months and was taking it 2-4 times a day. There are many options out there, and should all be discussed with your doctor.