For TM 43:
okay, you know how there are two ways to go through route 113?
1. the desert but you need to go-googles to do this
2. through the Fiery Path
When you go through either of them, you should come to a junction where there is a cooltrainer. he has a wailmer, a makuhita, and an electrike when you first face him. when you go upward from this trainer you should see another guy looking at a tree. talk to him, say "yes" to his question, and he'll give you TM 43, secret power. after this you can buy extra secret base goodies at slateport market. not the poke-mart, the actual market on the left side of the city.
For HM 08:
when you first get to mossdeep city, go stand in front of the gym, which is on the absolute upper right hand corner of the piece of land you are standing on. move to the left do that you are standing in front of the next house. if you were to go inside, there should be a guy who tells you what poke-blocks your first pokemon in your party likes. now, move again to the left to the next house. this one should be overlooking the beach. there should be a kid who gives you a king's rock right near/next to you if you say yes to his question. make sure you know where this house is, and go back to the gym.
beat the gym ([SPOIL]tate and liza[/SPOIL], and this guide is long enough already so i won't tell you how to beat them

) then go to the space center. if you go up the stairs at the lower-right hand side of town, then up another set of stairs near a white rock and a girl, you will see the space center. team [SPOIL]magma[/SPOIL] is trying to take over the space center. beat the grunts and [SPOIL]maxie[/SPOIL] then they will all leave. go back to the house i said about earlier, then go in. steven will greet you, then after a bit of chatting, will give you the HM 08.
i hope my efforts weren't wasted.