It makes no sense for you to try to understand programming and programming languages. In the position of a recruiter, your job is to answer two basic questions: 1) What do you want your website to do? If you want it to enable interactions with customers, you need a web developer. 2) What exactly do you want to build? If you want to run on tablets and mobile phones as well, you will need a mobile developer.
2. Find a specialist adviser
The candidates' CVs will not be enough for you to decide. Web and mobile development is not a field in which you could assess candidates based on their formal education or references from their former colleagues. You will really need an expert adviser. If you do not know any experienced developers personally, try to ask your local online community of developers to help you.
3. Tap into the psychology of developers
Good developers are highly enthusiastic about their work. Writing a code means both an art and a way to solve puzzles for them. When communicating with developers, you should therefore be honest in what you are looking for. Describe your idea and ask them about their point of view. Their interest in solving your task should be evident at first glance.
4. Do not hide your financial options
Do not get confused by their appearance. Even though developers usually do not follow the latest fashion trends, they know their price on the labor market very well and demand your respect. You should be completely honest to them in terms of the possible salary. If you have enough money, offer a competitive salary reflecting the current state of the market. If you have only an idea and almost no money, do not hide it. You may find a developer so excited by your idea that he will want to become your partner.
Bonus: Recommendations for Czech recruiters
If you want to use e-mail or social networks to find developers, read this article written by a Czech developer. The article very aptly summarizes the mistakes recruiters usually make when contacting developers.
More information about the IT professionals market in the Czech Republic is available in this article.