Best to do it manually. It's a pain in the arse process since the manufacturers usually offer out of date drivers. Some tips though.
If it's an Intel / Centrino based laptop then
http://downloadcenter.intel.com/ for drivers for the chipset (INF Update utility), network, wireless and possibly graphics if you have an Intel GMA graphics chip
If it's got an ATI graphics card, and you want to use it for 3D games,
http://www.omegadrivers.net, if it's got an nVidia card then just go straight to nvidia.com
If it has Realtek audio or networking then
http://www.realtek.com.twIf it has a Synaptic touchpad
http://www.synaptics.com/support/drive.cfmIf it has an ALPS touchpad, use the Synaptic drivers, they're a lot better
If you have unknown devices then right click on them, go to properties and details and you'll see a line like: PCI\VEN_10DE&DEV_0290&SUBSYS_22101682&REV_A1\4&63F8C69&0&0018. Put the VEN and DEV numbers into google (in this case 10DE 0290). There are a number of sites that collect those and will tell you what the hardware is
For everything else you may as well just get them from the manufacturers website