Whether you're just starting out on your weight loss journey, or restarting for the second, 5th or 20th try, remember the golden rule to get the basics down first. Sometimes people get mired in the details and lose the big picture, which is that a calorie deficit will result in weight loss. So let's get back to the basics!
I've posted this in other peoples posts when they were asking for help, but now that the formerly best stickies are no longer stickied, I think it's time to put it here by itself.
My MFP 'How-To'
Buy a food scale, weigh and log everything.
Do cardio if you want, and if you do, only eat back 50% of your calories (if you are losing faster than expected after logging for a few weeks, then up the % you eat back). Lift weights and hit your protein goal to help maintain muscle mass while losing.
Cheat meals that take you over maintenance will sabotage your efforts. Log the cheat meals too (falls under the 'log everything' rule).
Eat anything you want in moderation, keeping in mind that your diet will be easier to stick with if you chose foods that make it easier to stay under your calories without feeling hungry.
Also it would be a good idea to read some of the best forum posts such as:Calorie Counting 101Logging Accuracy, Consistency, & You're Probably Eating More Than You ThinkA Guide To Get You Started on Your Path To Sexy Pants
Weight loss is not linear, and if you see a brief stall, that is not the time to freak out! That is the time to go back and look at your logging, and make sure that everything is accurate (choosing diary entries that have the correct calories, making sure you have all your settings right including activity level - hint, this does not include exercise, and most people are sedentary), and if it is, then give it a few weeks.