2000 SAAB 9-5 white smoke in exhaust head gasket failure

2 years ago, car developed head gasket leak with dense white smoke from the tailpipe on start up at home. The engine was turned off within 2 minutes of this occurring Since this is a not primary car and I was too busy to deal with it, the car was not driven and the engine not started since then. My daughter would like to fix it up if possible. What possible other damage to the engine could have resulted from not attending to this problem for so long. What suggestions do you have to check for possible damage during the head gasket replacement and what other items would have deteriorated from sitting for 2 years? Eg fluid and electrical components