Try going to www.amazon.com and do a search on "raising boys."
There are many good books and you can read the reviews there too.
He seems to be testing you, and testing boundaries, and perhaps seeing where he all fits in to everything else and amongst the other children and everything going on around him. Maybe he feels lost in the shuffle. And yes, he's only 8 years old. They are still feeling their way around everything in the world. You are his Mom... the closest thing to him. Always remember that.... not alienating each other.
But there is right and wrong. Which we as parents, have to teach our kids. It can take time... and repetition, and consistency.. throughout their childhood. WE are guiding them.
One thing that can help, is having a weekly "meeting" with JUST ONLY him... and just talk story, 'allow' him to express himself, see what his life is, his concerns, his problems, his interests, his wishes & hopes... his thoughts about you. But don't take it personally. AND it can be a time to really "connect" with him.
I do that with my girl... and she REALLY likes it. She really bonds with me that way and feels "closer" to me. Then as a "family"... we all try to make a regular habit of "meeting" ALL together, just to talk about what is going on, and what is important or pressing, what is expected or needed, how THEY can help, or just to talk about things- openly, without lecturing or judgment. Kids really benefit by that, and by seeing that, and "how" their Parent(s) evaluate things by talking it out. It teaches kids right/wrong, how to problem solve, how to express themselves and how to be a PART of the family and that they count.
Making it a regular part of family life.
Do you tell him that it 'hurts' when he plays that game of "i love you but was crossing my fingers?" You need to tell him... and make sure he KNOWS that YOU are his Mom and you need to watch each other's back... that he is growing up, and he's your son... and there are certain things that are just mean and hurtful. As he grows up... he has to learn the proper ways of "loving" but that it is okay to talk to you about it all.
Allow him to talk openly... because as he grows up, you do NOT want him to not tell you things... and for him to know that YOU are the one he can come to for ANYTHING under the sun... that you are BOTH a TEAM.
Just some quick ideas...
all the best,
Susan