To make a new EDAnalyzer template, run

mkedanlzr name

To configure an output histogram file, add the following line to the configuration file:

process.TFileService = cms.Service("TFileService", fileName=cms.string('histograms.root'))

and the following to your module:

#include "FWCore/ServiceRegistry/interface/Service.h"
#include "CommonTools/UtilAlgos/interface/TFileService.h"
#include "TH1.h"
[...]
TH1F* h;
[...]
edm::Service<TFileService> fs;
h = fs->make<TH1F>("name", "title", 100, 0, 0);