Gguruusa gives some good help, but let me make it even more newbie friendly however, by continuing to read past this point you absolve me from any liabilities should your head explode:
ROM - when it's hardware, it means Read Only Memory. It's a chip that has information stored on it and you can't write to the chip. In this case, the information is the Windows Mobile operating system. As well, these chips are
Flash ROMs, which means that you can write to them, but more like a disk-at-once on a CD or DVD. So when you use an update from AT&T or HTC, it's actually writing to the flash ROM; that's flashing.
ROM - in software/firmware terms, it's actually like a disc image. When people talk about downloading or cooking or flashing ROMs, they generally mean these firmware images that will be written (flashed) to the hardware flash ROM.
Firmware - like software, but it resides in hardware and while it can have some information changed on it, most of it can't be altered except with an update program and usually gets flashed or updated all at once.
Examples:
- The BIOS on your mainboard, you can change settings, but to alter the BIOS you have to flash it.
- CD/DVD burners use firmware, it tells them how to write/read different media, and has the regional setting which can usually be changed like 5 times.
- iPods do too. When you use the restore or update functions in iTunes it's altering the firmware.
Kitchen - gguruusa explained it, but it's essentially a collection of utilities and scripts which will allow you to extract (dump) a ROM (the firmware version) from a device, or take apart a ROM, remove stuff, add stuff (general customising) and then reconstruct the ROM and even digitally sign it (with no signature it can't beflashed onto a ROM).
Cooking - is the above-mentioned customising within the environment of the kitchen.
CID Unlocking - CID = Carrier ID. If you bought your phone as part of a contract, it was probably locked to that carrier or service provider (i.e. SIM lock, only their SIM cards work) and it was locked so that only ROMs signed by them can be flashed. CID unlocking causes the phone to allow any signed ROM to be flashed. CID unlocked phones report themselves as SuperCID. With the Kaiser, I believe, they don't usually CD unlock, instead they install a...
Hard SPL - A little more of the basics to start with, when you power up your phone (i.e. boot up) the first thing to run is the boot loader. When the system boots, the boot loader loads the things the hardware needs to run into the memory. These phones have two boot loaders IPL and SPL. Intitial and Secondary Program Loaders. The IPL is very low level (like the BIOS on your PC) and the SPL loads the OS. It also makes your phone report itself as SuperCID. From what I understand, even if your phone is carrier unlocked, the Hard SPL also helps make it less likely for your phone to be bricked when flashing (bricked? turning your phone into an expensive paperweight) and prevent weird little problems when using custom cooked ROMs. You will need to intall a hard SPL. You may hear the term SSPL someday...
When you have a ROM to flash you'll usually have 2 files KaiserCustomRUU.exe, and RUU_signed.nbh. The nbh file is the ROM image. KaiserCustomRUU is the program which flashes the the ROM and this is the nice tidy version that extracts its tools and then deletes them when finished, otherwise you'll see a bunch of files the important one being ROMUpdate utility (RUU). Essentially it puts the phone into bootloader mode; it restarts and the screen shows a tricolour image (you can do that manually by turning off your phone and powering it up while holding the camera button, try and see, if you just reset at that point it will restart with no changes), the update software usually asks you to confirm at this point and then once it starts, you are commited. If you mess with it at this point, you could brick your phone. This is where the SSPL comes in, the phone is put into bootloader, the software loads the SSPL into memory which allows write access to the ROM so that it can be flashed.
Before you ever flash anything except a ROM provided by the carrier your phone came from, you need to know things about the ROM:
Which version Radio does it come with? If no radio, which radios will work with it?
Which versions HardSPL are compatable? (I think there are 4 versions)
Here is a guide for flashing the Kaiser.
This link is a thread in the XDA-Developers forums. Exit that thread into that specific forum and it is the Kaiser ROM forum. The sticky threads have the HardSPL links, FAQs and links a Radio thread. Read them.
This may seem daunting and you may think that the risk is too great, but if you follow instructions, you'll be fine. Take a look at some of the ROM offerings in the forum, they have screen pics so you can see what the ROMs look like and you'll see exactly the sort of things/improvements that you've said you want.
Other links:
The Kaiser Wiki
Glossary of Terms
A "Before you start" thread with informative links.