cmake on windows. Link libraries in folder - cmake

Question

Disclaimer: I'm new to cmake so i have no idea what I'm doing.
All guides and tutorials i find seem to think I'm running a 20 man team that needs to work together.
All I'm trying to do is put all my libraries in an include folder and lib folder.
In visual studio and code::blocks i just set up the linker in the IDE, but cmake is a little hard for me to wrap my head around.
I've set include and link directories with
include_directories(${PROJECT_SOURCE_DIR}/include)
link_directories(${PROJECT_SOURCE_DIR}/lib)
Then i try to
target_link_libraries(${PROJECT_NAME} jsoncpp)
This however produces undefined references. Is there a simple way to add and link libraries without me having to google and add a cmake module for each one?
Edit:
attempts:
target_link_libraries(${PROJECT_NAME} libjsoncpp.a)
error: undefined reference
target_link_libraries(${PROJECT_NAME} libjsoncpp)
error: cannot find -llibjsoncpp
target_link_libraries(${PROJECT_NAME} jsoncpp)
error: undefined reference
target_link_libraries(${PROJECT_NAME} C:/Repos/prosjekt-bad-racoon/lib/libjsoncpp.a)
error: undefined reference
target_link_libraries(${PROJECT_NAME} ${PROJECT_SOURCE_DIR}/lib/libjsoncpp.a)
error: undefined reference
Edit:
Full cmake file
cmake_minimum_required(VERSION 3.8)
project(prosjekt_bad_racoon)
set(CMAKE_CXX_STANDARD 11)
include_directories(${PROJECT_SOURCE_DIR}/include)
link_directories(${PROJECT_SOURCE_DIR}/lib)
set(SOURCE_FILES main.cpp Core.cpp Core.h Collider.cpp Collider.h Player.cpp Player.h Texture.cpp Texture.h AudioController.cpp AudioController.h)
add_executable(prosjekt_bad_racoon ${SOURCE_FILES})
set(EXECUTABLE_NAME ${PROJECT_NAME})
set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake_modules" ${CMAKE_MODULE_PATH})
target_link_libraries(${PROJECT_NAME} libjsoncpp.a)
find_package(SFML 2 REQUIRED system window graphics network audio)
if(SFML_FOUND)
include_directories(${SFML_INCLUDE_DIR})
target_link_libraries(${EXECUTABLE_NAME} ${SFML_LIBRARIES})
link_directories("${PROJECT_SOURCE_DIR}")
endif()
"C:\Program Files\JetBrains\CLion 2017.2.2\bin\cmake\bin\cmake.exe" --build C:\Repos\prosjekt-bad-racoon\cmake-build-debug --target prosjekt_bad_racoon -- -j 2
[ 14%] Linking CXX executable prosjekt_bad_racoon.exe
CMakeFiles\prosjekt_bad_racoon.dir/objects.a(Core.cpp.obj): In function `ZN4CoreC2Ev':
C:/Repos/prosjekt-bad-racoon/Core.cpp:3: undefined reference to `Json::Value::Value(char const*)'
CMakeFiles\prosjekt_bad_racoon.dir/objects.a(Core.cpp.obj): In function `ZN4CoreD2Ev':
C:/Repos/prosjekt-bad-racoon/Core.cpp:8: undefined reference to `Json::Value::~Value()'
collect2.exe: error: ld returned 1 exit status
CMakeFiles\prosjekt_bad_racoon.dir\build.make:236: recipe for target 'prosjekt_bad_racoon.exe' failed
mingw32-make.exe[3]: *** [prosjekt_bad_racoon.exe] Error 1
CMakeFiles\Makefile2:66: recipe for target 'CMakeFiles/prosjekt_bad_racoon.dir/all' failed
mingw32-make.exe[2]: *** [CMakeFiles/prosjekt_bad_racoon.dir/all] Error 2
CMakeFiles\Makefile2:78: recipe for target 'CMakeFiles/prosjekt_bad_racoon.dir/rule' failed
mingw32-make.exe[1]: *** [CMakeFiles/prosjekt_bad_racoon.dir/rule] Error 2
Makefile:117: recipe for target 'prosjekt_bad_racoon' failed
mingw32-make.exe: *** [prosjekt_bad_racoon] Error 2