Marie Browning's Melt and Pour Soap Making books are pretty good. Lots of info, projects & pictures.
Here's some more:
http://www.google.com/search?hl=en&tbm= ... ks&spell=1Before buying any though, check with your local library. Ours has quite a few of them.
There's also a lot of websites with great info, like
http://www.teachsoap.comJust google melt and pour soap making recipes and you'll get a lot
As for adding oils, a good rule of thumb is 1-2 TB (or 0.5 oz - 1 oz) per lb of mp base. Adding too much can really decrease your lather and/or cause oil seepage when finished.
For herbs, it's usually 1-2 tsp per lb of mp base. But you can add less or more, depending on how you like it.
Adding fruit or vegetables is a no no with mp. You'll probably see it in a lot of recipes, but don't do it. Fruit + MP = Mold
Most herbs will cause discoloration in mp soap. Not a bad thing if you don't mind.
I'm not sure how you could add very much apple cider vinegar to mp without making it too soft. Too much water type liquid will make your mp very soft.