lscpu will give you CPU info. Along with the commands paulsm4 already suggested will give you all of the info you should need.
Also you might take a look at one of the sysinfo scripts like
http://gsysinfo.sourceforge.net/ or
http://code.google.com/p/inxi/
$ inxi -F
System: Host craigevil Kernel 2.6.32-4.dmz.1-liquorix-686 i686 (32 bit) Distro Debian GNU/Linux squeeze/sid
CPU: Single core Intel Pentium 4 (UP) cache 1024 KB flags (sse3 nx lm) bmips 5587.56
Clock Speeds: (1) 2792.568 MHz (2) 2792.568 MHz
Graphics: Card Intel 82915G/GV/910GL Integrated Graphics Controller X.Org 1.7.4 Res: 1280x1024@60.0hz
GLX Renderer Mesa DRI Intel 915G GEM 20090712 2009Q2 RC3 x86/MMX/SSE2 GLX Version 1.4 Mesa 7.6.1 Direct Rendering Yes
Audio: Card Intel 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller driver HDA Intel
Sound: Advanced Linux Sound Architecture Version 1.0.21
Network: Card Intel 82562ET/EZ/GT/GZ - PRO/100 VE (LOM) Ethernet Controller driver e100 at port dcc0
Disks: HDD Total Size: 160.0GB (15.7% used) 1: /dev/sda 160.0GB
Partition: ID:/ size: 103G used: 24G (24%) fs: ext3 ID:swap-1 size: 5.25GB used: 0.27GB (5%) fs: swap
Info: Processes 116 Uptime 1:56 Memory 166.5/493.0MB Client Shell inxi 1.3.2