The problem is that consumer recording equipment is unshielded; cell phones, florescent lights, etc. radiate energy that can induce a current that becomes noise. My solution is to use professional equipment with laptop recording software. It is more money and trouble, but the quality is very high.
Step 1: Get a mic mixer for the PC, so that you can use professional mics. I prefer the ones that plug into the USB or FIREWIRE port so that I can bypass the internal sound card. Others connect to the “LINE IN” jack of your sound card, if it has one (not the computer’s MIC jack).
I no longer use the M-Audio MobilePre USB – 2 Channel USB Mic Preamp with XLR and 1/8″ Stereo Miniplug Mic Inputs
I changed to the Lexicon Lambda just because it works under Vista and Windows 7.
Step 2: Buy an appropriate mic. If the mic does not have a big, round, three-prong XLR plug, as in the photo above, you do not want it. This connector will shield you from most RF interference (very important in the typical office and anywhere near a PC). You will need some cables, too. Most mics do not come with one.
Audio-Technica U841A – Unipoint Boundary Condenser Microphone This is for recording a group of people. Must be placed on a hard flat surface (e.g. a table).
Shure PGX Series Wireless Microphone System – Includes: PGX4 Receiver, PGX1 Bodypack Transmitter and WL93 Lavalier Microphone (H6/524 – 542MHz)
PR 30 Dynamic Super Cardioid Studio Microphone — I love the warm, intimate sound of this microphone for podcasts and videos. (Of course, using this mic for a video requires post-production synchronization of audio with video, but that’s a whole ‘nother topic.) You’ll need a sturdy stand for this mic. I also suggest a shock mount and pop filter.
Step 3: Find PC recording software you like. Most is too complex, with emphasis on processing and altering the sound quality. Stay with something simple that will let you trim, splice, and save in the formats you want to use.
I for years I used Nero Wave Edit ( included in the Nero 9 package). With a couple clicks it takes out the background hum of air conditioning and florescent lights.
I have moved up to the pro-quality Adobe Audition. Almost as powerful is the free Audacity open source program.
Also, this article is good: