Most VPS/Cloud providers will optionally provide a LAMP stack ready to go out of the box. However, you typically will need to know how to:
- Configure hosting in apache
- Set PHP variables
- Install PHP add-ons, e.g. PECL/PEAR extensions
- Configure MySQL and optimize it
- Setup new MySQL databases and secure them
- Regularly apply OS updates
- Take backups of the server/application
...
And the list continues.
If this is for business purposes, I do not recommend trying to handle this challenge yourself if your business depends on this site. I always encourage people to evaluate the risks that a site security issue or failure could pose to their business. Try to quantify this risk and see if it makes sense to do it yourself. Also consider the time factor, unless you have a lot of automation, plan on spending at least 1 hour per month on routine maintenance.
Now if this is for personal use. Knock yourself out. I've never had a formal IT class but have built a business delivery IT services. When it comes to Linux, hand-on experience is key.
Just be careful with online forums. I find a lot of advice in there suspect. Sites like:
http://www.cyberciti.biz/
Offer some great tutorials that are usually more accurate than what you find in forums.