Once you have taken note of the appropriate preinstallation steps, you should be able to install FreeBSD without any further trouble.
Should this not be true, then you may wish to go back and re-read the relevant preparation section above for the installation media type you are trying to use, perhaps there is a helpful hint there that you missed the first time? If you are having hardware trouble, or FreeBSD refuses to boot at all, read the Hardware Guide provided on the boot floppy for a list of possible solutions.
The FreeBSD boot floppies contain all the on-line documentation you should need to be able to navigate through an installation and if it does not then we would like to know what you found most confusing. Send your comments to the FreeBSD documentation project mailing list <freebsd-doc@FreeBSD.org>. It is the objective of the FreeBSD installation program (sysinstall) to be self-documenting enough that painful ``step-by-step'' guides are no longer necessary. It may take us a little while to reach that objective, but that is the objective!
Meanwhile, you may also find the following ``typical installation sequence'' to be helpful:
Boot the kern.flp floppy and, when asked, remove it and insert the mfsroot.flp floppy and hit return. After a boot sequence which can take anywhere from 30 seconds to 3 minutes, depending on your hardware, you should be presented with a menu of initial choices. If the kern.flp floppy does not boot at all, or the boot hangs at some stage, go read the Q&A section of the Hardware Guide for possible causes.
Press F1. You should see some basic usage instructions on the menu system and general navigation. If you have not used this menu system before then please read this thoroughly!
Select the Options item and set any special preferences you may have.
Select a Novice, Custom or Express install, depending on whether or not you would like the installation to help you through a typical installation, give you a high degree of control over each step of the installation or simply whizz through it (using reasonable defaults when possible) as fast as possible. If you have never used FreeBSD before then the Novice installation method is most recommended.
The final configuration menu choice allows you to further configure your FreeBSD installation by giving you menu-driven access to various system defaults. Some items, like networking, may be especially important if you did a CDROM/Tape/Floppy installation and have not yet configured your network interfaces (assuming you have any). Properly configuring such interfaces here will allow FreeBSD to come up on the network when you first reboot from the hard disk.