What operating system is your laptop running? If it's a Mac, you can use MAMP. If it's a PC, you can use WAMP. I myself bothered to learn how to install the things "from scratch" by compiling them, etc., but these packages are pretty user friendly and can get you started easily.
As for accessing this laptop, I'm assuming you want these other computers and phones to access it using a browser. Please note that if these other computers/phones are not on your LAN then you will probably have to configure a router or firewall.
For example, I have a LAN here at my office. All the computers connect via ethernet cable (or wifi) to a router. The router is connected to the cable modem which provides internet service for the entire network. My local computers can all "see" each other by accessing a local IP address like 192.168.1.2.
If someone from Europe wants to connect to a computer on my network here in Los Angeles, I would need to configure my router to handle incoming HTTP requests (on port 80) by sending them to one of the machines on my network. How one does this depends entirely on one's router.
Additionally, if you take your laptop to starbucks, you need an entirely different solution because your laptop's IP address would change when you went from the coffee bean to starbucks to pete's or whatever. Offhand, I'm not sure how you would handle this situation.