Edit: Cookbooks aren't needed. Buy stuff you like and cook them together. As basic ingredients as you can. This is what I do, below:
Stir frys are a good place to start. But as said above, things will taste bland for a while.
When I make a stir fry, I don't use much seasoning at all.
1 pan with cut up meat, add chopped onions. Cook partway, add mushrooms and celery (if you have it) and cook on medium while the veggies cook. Add generous amounts of pepper and garlic. Salt if you like, but I try not to add any to anything I cook from scratch. You can add oil if you like, but if you have a good quality teflon pan, you don't need it as the meat, onions and mushrooms will provide enough juices.
Veggies: Usually carrots/broccoli and sometimes pea pods or string beans, baby corn cobs, one of those bags of frozen mixed veggies, etc. If the veggies are fresh, boil/microwave them first so they're slightly cooked. Put them in a pan with a little bit of olive oil and fry them up, again with pepper and garlic powder.
For rice, it's regular long grain white (can switch it up to a healthier kind if you like), but I put a teaspoon of butter in the water so the rice soaks it up and you need less later.
When it's all done I add a tiny bit of low sodium soya sauce - but if you can, get authentic asian sauce as there is less salt in them - and eat. I usually make enough for leftovers too, as it keeps really well and even freezes decently.
... All in all, I've found adding pepper and plain garlic powder (some people prefer onion or celery) to recipes really helps. Paprika, cayenne, etc. Go to a bulk food place and buy the tiniest bit of different spices (not mixes as they're full of salt) and see what you like.
Also, you can buy bottles of olive oil infused with different spices - they're more expensive, but work nicely.
... Adding garlic to everything makes it tasier, and is good for you. Just not everyone around you. Also, those packages of mixed vegetables in the frozen food aisles (just the veggies, make sure there is no sauces or anything) are great. Just rip one open, toss it in a bowl, nuke it, and there's half your dinner.
Also - when I make pasta, I fry up veggies (as I do above) and add those, so you're not eating as much pasta. I like to add chicken to the pasta too, goes well with veggies and is a bit healthier, too.
Best suggestions: Buy an extra freezer, stock up on butcher's shop quality meat when it's on sale, freeze it, and par-boil as many summer veggies as you can and freeze them too. Then you'll always have great summer-quality vegetables on hand. They're cheap this time of year (and for the next few months) and most veggies freeze well if you do parboil them. Do some research, though, as some veggies have different requirements of cooking/prep before they can be frozen.
Also, make your own pizzas, etc. DO some research, find what freezes well, and you won't have to cook big things every day of the week. I find a slow cooker works wonders - toss in spices, water, veggies and meat and leave - soup. Toss in spices, water, veggies and a hunk of meat - roast. Also good for pulled pork, stew, and pretty much everything. Get one.
Baked potatoes are also good - maybe try topping them with low fat sour cream and chives to be a bit healthier.
Crap I'm hungry now. And I need to get to the butcher's. I haven't had a slow-cooker roast in ages.
Also, grow a garden. Tiny Tim tomato plants fit in little pots and grow them in a window if you don't have a yard. Tons of cherry tomatos to add to everything or eat as a snack. Romaine Lettuce would work well, too, if you buy a long, narrow planter. Doesn't need a ton of soil. Grow your own herbs, too, as fresh ones add a huge punch. If you do have a yard, grow carrots. If you pull them, don't wash them, just knock the dirt off and let them dry in the sun for a day or so, then put them in a bag (with holes in it! It HAS to breathe) and stick it in the crisper in your fridge and they will last months. Research plants to suit your climate and living space. Most plants only need occassional watering and thinning (carrots and lettuce), and that's it. Nice and easy.
My lettuce is sprouting nicely in planters about 6 inches wide by two feet long. And my Tiny Tim's are coming along well, too, in small round pots (diameter about 4-6 inches, or two in a bigger one). My lettuce is on my patio and the Tims are inside. They do get a lot of sun, though as I have a south-facing unit. Am also growing carrots, green onions (also good in planters) and more lettuce at my parents.
Maybe see if there's community garden spots near you, if you don't have a yard?
For sweet treats, I have chocolate milk. Soy milk as I can't actually have dairy, but that's my treat. I also don't buy pop or chips anymore - can't eat them if they're not there.
And always eat before you go grocery shopping. It does really help. ANd make a list and don't deviate.
it really works and if your living alone or cooking for yourself even better.