You asked

Nutrients: how do you make sure baby is getting the right nutrients?

When you are introducing solids, it must be done slowly (with just one or two spoonfuls) and should be done one food at a time, giving a few days in between introducing any new foods so that you can assess any possible allergies.
You should make sure your baby is enjoying a balanced diet. This means ensuring that they have all the protein, fibre, calcium and other minerals and vitamins that they need in their new solid food diet.  It’s a good idea to base your baby’s new meals around starchy foods which provide lots of energy for a growing child, but you will also need to ensure that your baby’s meals are rich in protein (which supplies the body with amino acids which are known as the body's building blocks) and iron (essential for growth and development). 
One of the most common natural deficiencies is that of iron, which can affect growth and development. Babies are born with a store of iron, which lasts approximately 6 months, after which time they will need to get their iron supply from their diet. With a vegetarian diet, the source of iron must be obtained from cereals and vegetables such as peas, beans, lentils, nuts and seeds. As long as there is no history of asthma, allergy, eczema or hay fever in the immediate family, smooth peanut butter can be introduced into the solid food diet from 6 months. Do not give whole nuts to children under five. Finely chopped nuts or nut butters are fine. 
Calcium is essential for healthy teeth and bone development and is supplied to your new born baby through their milk feeds, and remains the same as you begin to wean. However, you can include dairy products when preparing meals, such as cheese, yoghurts and fromage frais which are a rich source of calcium. You should not feed your baby cow’s milk before they are 1 year old, and babies under 2 should only be given whole milk, as reduced fat milk does not contain all the vitamins and fat required for a growing baby. There are also various minerals and vitamins required which can be obtained from fruit and vegetables.
Good sources of each of these food groups are as follows:
Fibre & Starchy Food
Breakfast cereals
Protein & Iron
Lean red meat is a good source of iron and protein
Eggs (very well cooked until the yolk and white are hard)
Oily fish such as salmon, tuna and sardines are also excellent sources of iron and protein
Minerals and Vitamins
Many essential minerals and vitamins can be found commonly in fresh fruit and vegetables.
Vitamin A
Commonly found in carrots, avocados, spinach, dark leafy vegetables, kiwi, and prunes
Essential for vision and growth.
Vitamin B2 (Riboflavin)
Commonly found in mushrooms, carrots, broccoli, turnips, spinach, apples, prunes, and grapefruit.
Essential for growth, and breaks down fat and carbohydrates
Vitamin B6
Commonly found in cabbage, prunes
Essential for a healthy immune system, healthy red blood cells and normal growth
Vitamin C
Commonly found in avocados, banana, green and red peppers, turnip, cabbage, kiwi, tomatoes, blackcurrants, strawberries
Essential for iron absoption, and for the growth and repair of tissue, for healing wounds and maintaining a healthy immune system
Vitamin E
Commonly found in sweet potatoes, leafy vegetables, peas
Essential for healthy skin tissue, eliminating free radicals in the body and helps to form red blood cells, as well as assisting the body to break down Vitamin K
Vitamin K
Commonly found in green vegetables, cauliflower
Essential for clotting blood
Folic Acid
Commonly found in dark green leafy vegetables, root vegetables, dates
Essential for healthy cell development and red blood cells
Commonly found in avocados, celery, dates, apricots, raisins, green leafy vegetables
Essential for healthy growth of teeth and bones,and for blood clotting
Commonly found in mushrooms, carrots, squash
Essential for healthy teeth and bones
Commonly found in celery, mushrooms, grapes, oranges
Essential for thyroid hormone development
Commonly found in mushrooms, brussels sprouts, potatoes, spinach, tomatoes, bananas, strawberries, oranges, dried fruits
Essential for healthy nerve and muscle maintenance, and for distributing water in the body
Commonly found in dark green vegetables and pineapple
Essential for muscle contraction maintenance especially the heart and nerves
Commonly found in pumpkins, turnips, celery, string beans
Essential for nerve maintenance and distributes water in the body
Commonly found in mushrooms
Essential for healthy immune system function, growth, sexual development and reproduction
Ideal foods to begin with when you are starting to wean,include pureed vegetables or pureed fruit, or baby rice or cereal mixed with your baby’s usual milk.
Once your baby is used to the pureed food, you can start to introduce mashed foods that contain soft lumps, which your baby can chew on even without teeth.
When your baby is used to light lumps, you can begin to introduce new textures such as blended mini dinners with fish, meat or chicken included (making sure that everything is cooked through and that any bones are removed).  You can also try to introduce new tastes by using stronger vegetables in your mini blended dinners such as spinach and cabbage. For more recipe ideas why not visit our recipe section?
Although you are still feeding your baby milk at this time, you can also introduce new liquids such as water in a cup with handles and spouted lids (never in a bottle). You can give your baby fruit or vegetable juice but you should only offer at mealtimes (to help protect baby’s emerging teeth). Make sure it is diluted well, using at least one part juice to ten parts water.

More questions

Fibre is important in your baby's diet but should only be present in small amounts as it can prevent the absorbtion of important minerals.
Fat is a vital source of energy for your growing baby.
Gluten is contained in foods such as wheat, rye, barley, and oats which are alll good sources of iron and fibre.
Honey should never be given to a baby under 12 months due to the risk of botulism poisoning.
There are lots of wonderful first foods for your baby to try including puréed vegetables, fruit, and baby cereals. 
There are lots of great ways to easily prepare and cook food for your baby.
A good breakfast is vital to ensure your baby is getting the best start to the day. 
In the beginning you should only feed your baby a spoon or two of solid food a day. This will gradually build up over a period of a weeks until they are enjoying three meals a day.
It is essential that you provide your baby with a well balanced and nutritious diet. There is a wonderful variety of foods to choose from.
If you're having problems weaning your baby it may be that they just aren't ready. Take a week or two to resume milk feedings and try again.