need register form and user poster

hello,
i tryed servial plug-in’s for register form and some for user that could make post’s. But problem is i can’t fin non of plug-in that would work correctly. So if any1 know a widged that enables register for users and that logging in would do properly please tell me neme of widget-plugin. And then if you know any plug in that under pages user could meke a post. That’s all i need.