Hi Fyrdog,
I live in Sanford and from I-4 take hw 46 and go west over the wekiva river in Lake County. After about 20 minutes or so you should see the onramp on the right onto 441. Take 441 for a ways and look for a right onto hwy19 which takes you north towards Scrub. Once you see the signs on 19 that you are entering the Ocala Forest go about 10 more minutes and you should see on your right hand side a blue sign with yellow letters that says rd 445. As soon as you see 445 you need to get ready to make a left a few blocks up onto a dirt road which leads you onto the high powerlines and ultimately 7 miles down a dirt road to Scrub. As soon as I pass 445 on my right I always know where to turn left because there is a small brown cabin used as school bus stop for the kids to wait in the morning. That is the street you turn on that takes you to the lines. Also you will know you went too far if you go under the powerlines because the street (forest rd) for Scrub is just before that.
If you zoom in on this map you can see route I mentioned
http://www.mapquest.com/maps/map.adp?formtype=address&searchtype=address&country=US&addtohistory=&address=&city=mount+dora&state=fl&zipcode=What day are you heading up there? If you want send me a message and I will give you my phone # so you can call me if you get lost.