HELP!!!!

OK here's my rant.  Does anyone else have problems with blogger, said problems, space on your post?  When I insert a picture, it seems like there is always a huge space before or after it, which I can't seem to figure out.    I always have to go back and redo space in the HTML  and then it screws up and so and so on.  Do you have tips that I can use to get my posts spaced right?   I have tried several things and nothing seems to work.  It is probably some little simple thing that I just haven't figured out yet.  Also, I have problems with alighnment.  If there is a tutorial to explain these things, please tell me.  So many of you have such lovely blogs and then I preview mine, and it seems a mess.  Any tips will be greatly appreciated.