1st You should analyze your own idea of a bicycle. Just make a few essential bench marks.
2nd Look for informations: Take a look to cycling shops, cycling magazines and internet performances of cycling producers. Internet shops can help to find the right way, but avoid buying a bicycle in a web shop, finally.
3rd Take a preselection of a few cycling producers with some basic models.
4th Go to a cycling shop for discussion, testing some models, make clear essential sizes and techniques. Be aware of way of repairing the bicycle and how to find spares.
5th Discuss with your friends and in this forum about your preselection and the still existing questions.
6th Make clear about everything and sleep one night.
7th Are you still sure about what you want?
8th Go to your favorite cycling shop and start final discussion. Give order for your bicycle.
9th Be flexible if the cycling shop has to change some details, but assure yourself, that's necessary.
10th If the bicycle is ready, pay it at once. It's now yours. You are receiving now your new love. Take a first ride, test everything is okay and enjoy it like a new start in your life.

It's now finished.