Which OS are you using? What c++-compiler are you using?
Do you intend to make a static library (.lib, .a) or a dynamic link library/shared library (.dll, .so)?
***Under Unix/Linux:
-Create a static library:
1) g++ -Wall -c func1.cpp func2.cpp func3.cpp
Results in three object-files func1.o, func2.o and func3.o
2) ar -cvq mylib.a func1.o func2.o func3.o
Creates the static library mylib.a
-Create a shared library:
1) g++ -Wall -fPIC -c func1.cpp func2.cpp func3.cpp
Creates three object-files, that can be used for dynamic-linking
2) g++ -shared -Wl,-soname,mylib.so.1 -o mylib.so.1.0 func1.o func2.o func3.o
Creates a shared library called mylib.so.1.0
3) Move the library to suitable location
4) Make to symbolic links:
ln -s mylib.so.1.0 mylib.so.1
ln -s mylib.so.1 mylib.so
5)Update the linker cache