Well my home is almost 100 yrs, because I bought it for a song and the area that its in has trebled in prices within the real estate market, so I dont mind spending extra...
The first thing I looked for was dry rot....most important for a house that old.
After purchasing, the next thing I did was to repile the whole home
2. had all the wiring and fuse box replaced
3. re plumbed and put all new vanities etc throughout the home
4. new kitchen designed, and fitted by the builders-trust me, dont get any of those DIY kitchens because with a home of that age you will find that the walls are not square, and you will end up with gaps in your new kitchen fittings, between the bench top and walls
....and yes Im still renovating