I need some ideas...

BunkyBumBum

I don't want to buy a workout video, but I need some ideas of what I can do with just a yoga mat and a resistance band at home during the day and I'm hoping someone has a general "if you do this set you burn x calories" type of thing because I haven't had luck tracking strength training exercises yet.

My story - I joined MFP awhile ago but I quit and went back to weight watchers (I have lost and kept off 70 pounds for 3 years, a year and a half on weight watchers and a year and a half off). I have 20 more pounds to lose, but I hit a wall with weight watchers, since May of this year I have gained and lost the same weight over and over, some periods I would go WEEKS where I would gain exactly 1.6 pounds one week and lose exactly 1.6 pounds the next week. Finally I decided I'm wasting my money doing the same thing over and over when it is clearly not working, I intend to join a gym in a couple weeks (waiting for a promotion) but in the meantime I need to figure something out because my calorie target is 1360 and I'm having a very hard time sticking to it without exercise and I feel like I need to work on building core muscles and when I do get my gym membership, that will primarily be for the classes and the cardio. To top it off, with the weather turning cold I haven't been able to get out as much so my usual walking is cut back dramatically.

Any suggestions are welcome, I'm a total beginner at this at home fitness thing, I mean, I know about crunches and squats and push ups, but beyond that I'm not really sure what a good "work out" would be. I can commit to 30 minutes twice a day for core training.