Firstly, to ensure that they feel welcome it's important to have things set up and ready for them to use from their first day. This can be anything from hardware, to user permissions to even providing them with a notebook and pen. I've seen it all too often, and experienced it myself on some occasions, turning up to my first day in a new role, and not having a pc, and on one occasion not even having a desk. In order to feel part of a company, and welcome, then it is extremely important that the company is ready for you to start, not only from a financial aspect (ie. you sitting around doing nothing and getting paid, generally isn't productive for the company), but I love starting a new job and getting my teeth into something and hitting the ground running.
Secondly, introductions to people you will be working with, be it other members of the QA team, other members of the Dev team, or even other members of the Business who you will be liaising with on a regular basis. This does work both ways, if, as a new starter, you don't know someone, don't be afraid to ask who they are and introduce yourself, 9/10 the other person will be wondering who you are too!
Next up, is to let the new starter aware of any training that they are entitled to, if you let them know that there is training in place, and you can progress, it will instantly make someone feel at home and a part of the team.
Often, a good way of getting someone to know about the business and any training that is offered, can be in the form of buddying, this doesn't have to be in relation to QA specific queries, but any query that the new starter has (from something mundane as where can I get good coffee to something work related) can be answered by the buddy, or the buddy will more often than not know who to ask to get an answer. If this buddy system is in place over a prolonged period of time, the new QA will eventually be in a position to be able to do buddying themselves and help new members of the team feel welcome and at home in their new role.
Also, an induction pack is invaluable. This can be in the form of a wiki, or a hard copy of a document. This can include company specific things, but to generalise, it would be useful to include things like release processes, information on a regression pack, an overview of systems architecture, any third party services that are used, information around any automation pack and how the test environments are set up in your company. If the new starter wants to be involved/learn more around any of the areas then at least they have a starting point at which to begin with.
And finally, and the one that is often most enjoyed..... Drinks :) Nothing makes someone feel more welcome than going out and having a drink with them, or even a lunch if they don't drink. Speaking to people outside of work definitely adds another dimension to a work relationship, and will almost certainly make the new starter feel welcomed :)
As a side note, when creating this blog, I decided to start messing around with MindMaps, and found it extremely useful... I'll definitely be trying to use it where I can when it comes to test planning etc. I'll share my mindmap for this post here:
I'm sure you can expect a blog post on mindmaps in the near future!