The BBC good food website is fantastic - tens of thousands of recipes, searchable by key words such as 'Healthy' and 'Quick and Easy'. I heard rumblings that it may be taken down in the near future, so save as many as you like to your own computer.
thefoodchampions.org (sorry, can't link properly on phone) is a great website - free recipes created by food/sports scientists for the GB Olympic team. That stuff is seriously healthy.
The nutritionist (or dietitian? Anyone can call themselves a nutritionist, a dietitian has actual qualifications) sounds about right.
Healthy balanced diets contain mostly vegetables, pulses, seeds, nuts, grains, fruit. Although it is entirely possible to get all the nutrients you need from a vegan diet, I find it tastier to include meat fish eggs and dairy.
Carbs - potatoes with the skin on, brown rice (needs cooking for ages), brown bread. They contain more nutrients and fill you up way longer.
But yeah, 'eat mostly plants' pretty much covers what a healthy diet is (for adults anyway - kids need more calories per gram from their food than adults do, you don't have to stop buying fish fingers) , and most diet books are selling an expensive fantasy.
If you suddenly increase the fruit and veg in your diet you may find it has - ahem - effects on your system. It won't last long, don't worry. Also, if you suddenly decrease the sugar in your diet you may get the odd headache/feel tired at first. It's temporary.
Like pp said, it takes a while to learn not just different recipes, but different ways of thinking about food. Don't be hard on yourself in the meantime. If you make one healthy meal this week, that's an improvement. Build up slowly, and if there's a night where everyone ends up with pizza and chips, well, sod it, the sky won't fall in.
Eat before you go food shopping - you 'll buy less junk.
Have a think about if there are other areas of your life where you would like to make changes. I don't wish to be intrusive, but speaking for myself, the times when I have taken advantage of my corner shop's 3-chocolate-bars-for-a-pound offer, I wasn't eating because I was hungry.