I'd put the sketch on a specific layer, then go into Drafting application, turn OFF the dwg and orient the XY plane to the same plane as your sketch and start inserting text. Sketch and text reside on same layer. If users do not wish to see text (because it will be visible at all times) they can shut off that particular layer.
Tim Flater
NX Designer
NX 9.0.2.5 Win7 Pro x64 SP1
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB