Factory Service Manuals for anything older than a '97 XJ are hard to come by. Pick up the Haynes manual (Id prefer Chiltons if you can find one) first, then get a multimeter (research online how to use one). If youve lost all of that electrical stuff at once, start with the fuse juncture box either in the engine bay or under the passengers side dash (could also be drivers side). Look for corroded or fried contacts around the fuses.

And for the love of Pete, next time disconnect the negative battery cable from its terminal before doing any additional work. It prevents shit like this from happening.