i cant PM yet, but here is a link to instructions and tutorials to all of the example projects that are built in to the ArduinoIDE software... of coarse different projects need different items like resistors, LEDs, servo's, motion sensors, etc... I got a beginners kit a couple X-mas's ago that came with a ton of sensors and goodies.. i think the 37-sensor kit goes for about $40, and the basic beginners kit with led readouts and a bunch more stuff was about $60... you dont need those for the temp humidity project tho'.... but once you've made one smart project work your gonna wanna make other ones.. 
Built-in Examples | Arduino Documentation
Learn the basics of Arduino through this collection tutorials. All code examples are available directly in all IDEs.
www.arduino.cc