1) ./bootstrap.sh prefix=/usr/local

2) ./b2 install

So the libs are: /usr/local/lib

The headers: /usr/include/boost

Actually I was interested in some stuff with asio. So I started with this code from the tutorial.
http://www.boost.org/doc/libs/1_61_0/doc/html/boost_asio/tutorial/tutdaytime1/src.html

 g++ -Wall  main.cpp -o zclient 
/tmp/ccxx7PrW.o: In Funktion `__static_initialization_and_destruction_0(int, int)':
main.cpp:(.text+0x52e): Nicht definierter Verweis auf `boost::system::generic_category()'
main.cpp:(.text+0x53a): Nicht definierter Verweis auf `boost::system::generic_category()'
main.cpp:(.text+0x546): Nicht definierter Verweis auf `boost::system::system_category()'
/tmp/ccxx7PrW.o: In Funktion `boost::system::error_code::error_code()':
main.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x17): Nicht definierter Verweis auf `boost::system::system_category()'
/tmp/ccxx7PrW.o: In Funktion `boost::asio::error::get_system_category()':
main.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[_ZN5boost4asio5error19get_system_categoryEv]+0x5): Nicht definierter Verweis auf `boost::system::system_category()'
/tmp/ccxx7PrW.o: In Funktion `boost::asio::detail::posix_thread::~posix_thread()':
main.cpp:(.text._ZN5boost4asio6detail12posix_threadD2Ev[_ZN5boost4asio6detail12posix_threadD5Ev]+0x26): Nicht definierter Verweis auf `pthread_detach'
/tmp/ccxx7PrW.o: In Funktion `boost::asio::detail::posix_thread::join()':
main.cpp:(.text._ZN5boost4asio6detail12posix_thread4joinEv[_ZN5boost4asio6detail12posix_thread4joinEv]+0x2b): Nicht definierter Verweis auf `pthread_join'
/tmp/ccxx7PrW.o: In Funktion `boost::asio::detail::posix_thread::start_thread(boost::asio::detail::posix_thread::func_base*)':
main.cpp:(.text._ZN5boost4asio6detail12posix_thread12start_threadEPNS2_9func_baseE[_ZN5boost4asio6detail12posix_thread12start_threadEPNS2_9func_baseE]+0x29): Nicht definierter Verweis auf `pthread_create'
collect2: error: ld returned 1 exit status

I have to add that the simple programm in the starting guide worked properly 
http://www.boost.org/doc/libs/1_61_0/more/getting_started/unix-variants.html#link-your-program-to-a-boost-library

via
g++ -Wall main.cpp -o zu

It worked in Code::Blocks as well (without any additional information).

Even the second simple programm (same link) I managed to compile giving the full path:
g++ -Wall main.cpp -o extractmail /usr/local/lib/libboost_regex.a

At no time I had not to instruct the compiler about the headers. I was wondering. So it must have anything to do with the libs. 

Coming back to my asio- example. Do I need libs for it? I guess is has something to do with the expression -lboost_system. I used it without understanding it. But it did not help.

Actually I would appreciate if was able to use Code::Blocks but I did not manage to give Code::Blocks the correct instructions. I 

found some hints, at least amounts of hints ... But it did not work at all.

If somebody is able to explain it (for idiots) ... This would be great.

Thanks

Hermann