I'm a little stuck with what I should do first on my layout?
What is the order that I should follow to make a great layout?
Whats the good order of Texturing, making the terrain e.g. hills, lakes, placing objects, doing trackwork?
also can somebody help me with making a town look like a town, I'm going for a Australian style because its Thirlmere to Buxton.
As Andy says there are many, many ways of doing things.
First, before you build your mega-route of all times, start small. A small route can always be expanded and then some. I started my mega-route 10 years ago and since then it has grown from a little over 4 baseboards to something that is around 180 miles long the last time I checked. I have renovated and changed baseboards as my building techniques have gotten better, but the overall theme has remained the same including the locations of many towns and cities.
Don't rush things, let them develop on their own. If you rush the building process, you'll be frustrated with how the results come out.
Plan and research. This is probably the biggest part of a route building process. Look at maps, photographs, aerial images, books, anything that has information on your route. This works whether this is fictional or real.
and finally, have a purpose for the railroads existence. Is it a mine to factory? Is it a commuter railroad serving a big city, or is it part of a larger network which sees a bit of everything. The purpose not only makes the route more realistic, it gives you reason to run the trains. Just running trains in a circle or back and forth for the sake of running trains gets pretty stale after a short time.
Regarding making lakes, rivers, towns, etc. Download and open up existing routes from the DLS. These will give you an idea of how other people did things. If you use DEM (Digital Elevation Map) data, the overlay maps will have roads and locations of buildings. This will help you build your cities and towns, and will eventually give you ideas how to build your own without the use of maps as a guide.
For other things such as track laying and signaling, check out the various posts and tutorials on this.
Here's an excellent tutorial on track laying and signaling which will get you up and running fairly quickly.
http://trains.0catch.com/tutorial.html
The Surveyor's and Operations forum has a sticky on route building techniques. Read through the numerous posts on how to make mountains, cuts, place bridges, among many other things.
John