Dwight ... I did the same thing when I first got my Lowrance Elite 5DSI unit. I downloaded and printed out the Operation Manual, too.

Luckily I got 2 sets of power/transducer cables in the deal (bought it from a member off the classifieds). I already had a portable Jumper Battery. I put one set on the boat & used the other set to "play with" the unit in the comfort of my living room. Shortly thereafter, I found the website of the KDFWR that has the GPS coords of all the habitats they placed in our lakes. Back then they were in a GPS format that my E5DSI did not recognize, so I wrote them down and then found a website that converted them over to the format the unit understood. I wrote down those GPS coords & fired up the unit on the jumper battery, then proceeded to manually enter all 200 coords for the three lakes I fish most often. Might have taken me a couple hours, but once I got a rhythm down it went pretty smoothly.