That's not a lot of questions, i think it's what everyone should be asking before committing to a tattoo - i think a lot of people (unfortunately) just go and get whatever they're into that week, or whatever their friends are into without thinking, and sometimes that's o.k as it reminds them of that time later on, but a lot of people also regret it, and have to get cover-up after cover-up just to hide their mistakes. thinking first is always a good idea.
If you have an idea of what you want, bear in mind that different artists are usually better at different things - everyone develops a style they're best at, and whilst most artists can do most styles, it pays to find someone who's really into whatever style it is you want. go and look at their portfolios - preferably ones you can look at in your own time so that you don't feel pressured to say you like it all if you don't. remember that you are the customer, and it's your responsibility to go with what you like - don't feel bad about trying different plces and artists - some are just better than others, and if you look at a lot of work, you'll soon start to see the difference between what's poor, what's o.k, what's good, and what's excellent. With money, better artists will charge more - it's just the way of things, but always go by the quality of work, as there will be poor artists out there trying to charge lots - there will be an average price in your area - some charge a flat rate, and some by the hour. shop around, but ulimately , it's a lifetime investment, as you know, so find someone you really like, and if it's more expensive (for good reason) then i'd say it's worth saving up until you can afford it rather than going to someone cheap who won't give you what you want. You can hire people to design for you, but good tattoo artists should be able to do this based on your ideas and an overall style - again - look through their portfolios for original designs (not flash) and see if you like their style,
hope you find what you're looking for!