There's no fixed answer to this question, because notebook hardware is constantly updated, and getting the X display, sound, PCMCIA, modem, and so forth, working, can take a good deal of effort.
Most notebooks currently on the market, for example, use "Winmodems," which often do not work with Linux because of their proprietary hardware interfaces. Even notebooks which are certified as "Linux compatible," may not be completely compatible.
Information about installing Winmodems in general is contained in the Winmodems-and-Linux HOWTO. (Refer to "Where Is the Documentation?")
You can find the most current information, or ask other users about their notebook experiences, on the linux-laptop mailing list, which is hosted by the vger.redhat.com server. (Refer to "What Mailing Lists Are There?")
A mailing list for Linux on IBM Thinkpads has its home page at http://www.topica.com/lists/linux-thinkpad/.
Another Thinkpad mailing list is hosted by http://www.bm-soft.com/. Send email with the word "help" in the body of the message to email@example.com.
There is a Web page about Linux on IBM Thinkpads at http://peipa.essex.ac.uk/tp-linux/.
The Linux Laptop home page is at http://www.cs.utexas.edu/users/kharker/linux-laptop/.
For information about interfacing peripherals like Zip and CD-ROM drives through parallel ports, refer to the Linux Parallel Port Home Page, at http://www.torque.net/linux-pp.html.
If you need the latest version of the PCMCIA Card Services package, it is (or was) located at ftp://cb-iris.stanford.edu/pub/pcmcia/, but that host no longer seems to be available. Recent distributions are on ftp://metalab.unc.edu/pub/Linux/kernel/pcmcia/. You will also need to have the kernel source code
installed as well. Be sure to read the PCMCIA-HOWTO, which is included in the distribution.