Highland is a region in Scotland.
Cities, towns and villages
There are far too many mountains in Scotland to cover them all here.
Some popular mountains by group (pronunciations of difficult names in italics).
Northern Torridonian mountains
Mountains of Torridonian sandstone north of Ullapool.
Glencoe and Fort William
A range second only in height to the Nevis range, located east of the A9. There is a railway up Cairn Gorm (which is not the highest). However you make the height, it's relatively easy to walk more peaks, with excellent views. It is the only area in the UK where wild reindeer can be seen - re-introduced from Scandinavia after becoming extinct in Scotland. Red squirrels are also to be seen in the remains of the old Caledonian Pine Forests.
Sad but true - owners of land in Highland, often absentees, have not on the whole shown much consideration for their tenants. Some of what may appear lovely, natural, unspoiled areas were actually forcibly cleared of their human inhabitants in the interests of deer hunting or sheep farming. 
The main airport is in Inverness, it's operated by Highlands and Islands Airports, a company that also owns and operates several other smaller airports in the northern and western islands of Scotland.
ScotRail operates several trains in and around the Highlands. You can buy tickets and get updated schedules on their website. Scottish railway system is well integrated with the UK's rail system, see also Rail travel in the United Kingdom.
If you don't own a car, or you don't want to hire one, then your best choice to travel around the Highlands is by bus. There are several but companies operating in the region: Citylink, Stagecoach, Megabus and National Express. Traveling by bus may be slower but you'll be able to enjoy the scottish landscape.