What actions are associated with registering a company/software name?

I live in Austria, Europe.
I am a software developer and I would like to distribute my software under the name of my company. So I consider the following:

I might want to register the name for my software. If I do so, what do I have to be careful about ? How do I know if the name I would like to register is available and differs enough to be accepted ? What are the main steps of registering a company name? Is the name registered and protected worldwide ? What costs are to be expected ? Which actions do I have to take ?
Is it wrong to register after a successful launch of the software ?
What about the logos and restrictions ? Are they very fussy about similarity of logos ?

I am sure here are a lot of people who dealt with these problems and I would really appreciate your personal experiences with registering a trademark/company.

So, broken down I'd like to register: a) company name and logo

b) software name and logo

I especially would like to know: a) costs

b) actions

c) difficulties

I am trying to answer questions related to the company registration(not the Software name and/or software/company logo) based on my experience in Hungary. I am sure, in Austria also you will have similar process.

Q:What are the main steps of registering a company name?
A:I registered my company name in Hungary through a known lawyer. Main steps are documented here:
http://www.doingbusiness.org/data/exploreeconomies/hungary/starting-a-business Q:Is the name registered and protected worldwide ?
A:No it was in Hungary only in my case.

Q:What costs are to be expected ?
A:All cost that I paid are almost same as listed on the link I gave above.

Best regards and goodluck,
Ajay

I run a software company in Austria, so here's the specific info for Austria :)

Trademark:
First, are you sure you need to trademark your software name right now? How big is the risk that someone takes the same name as your startup? Even if someone somehow took the same name, they surely wouldn't put you out of business by that.
So I would wait with the trademarking until you get the product off the ground. Also, I don't know anything about that so the rest about the post will be about registering the business only.

Company: Registering a simple company like "Einzelunternehmen John Doe" ("sole proprietorship John Doe") is easy. Just visit the chamber of commerce. They have a special service for founders where they give you all the paperwork you need (it's not much). If you have any legal questions before you get started, they can refer you to people within the chamber that will help you. Then, you fill the paperwork out and bring it to municipal authorities. The company is immediately registered.
Just one thing: inform yourself about the different types of companies in Austria. Generally, a sole proprietorship (Einzelunternehmen) is the easiest to start and also pretty good tax-wise. The disadvantage is that you have full liability with your private assets. (which is probably not an issue in a one-man software business)

Afterwards, you need to deal with a few legal issues (registering for social security, and registering with the fiscal authorities). However, you can just learn that as you go along and it's no big deal.

The costs are less than 100 for registering. Afterwards, the two main costs are chamber of commerce fees (about 100 / year) and social security (about 200 / month in your first year).

There are no particular difficulties (in the registering process) that I'm aware of.

If you live near Graz or Vienna and would like to get in touch, you can find my email in my profile.