Hey all. I just passed my ICND1 with a core of 897. The only source of study was watching the 78-video series on CBTNuggets for 100-105.
I think something that really helped me was writing the labs using pen & paper. Drawing the topology and using sheets of paper for each network device for the handwritten CLI. I then took those sheets, transcribed them in to Packet Tracer and ran the simulation. If something didn't work, I'd find the problem, scrap all the sheets and re-write everything.
I'm now on 200-105, fingers crossed!