I am assuming you have a second gen touch however if not the same parts are available for the first gen touch as well.
Digitizer
LCD
Bezel
You will need a couple of plastic opening tools which I already had but a set were included with the parts when they arrived. The plastic bezel surrounding the front glass has clips that hold the whole thing in place. The glass is adhered to the bezel with double sided tape. I inserted the tool in the right hand side between the plastic bezel and the chrome and then slowly moved it up to the top right corner to pop the first clip and then proceeded to move back down to the bottom right corner, then back to the top right and over to the top left (This is where the digitizer ribbon cable connects to the mainboard) then down to the left side to the bottom left corner which basically left only one clip at the bottom attached. The ribbon cable connector just pops up to release. The last clip at the bottom is the hardest to release but just gently persevere and it will come away.
If it is just the front glass that is broken and your LCD is fine then that is all you need to remove apart from the home button assembly from the old bezel which can be removed by using a razor to gently cut the tops of the 5 plastic mounting nubs after which it should just slide off. To connect it to the new bezel I just place it on the mounting pins and then using a soldering iron softened the tops of the plastic mounting pins and pressed them down spreading them to lock it in place. If you do not have a soldering iron you could just heat up the tip if a small screwdriver to achieve the same result.
Although they can be found with the adhesive applied most of the plastic bezels on ebay do not come with the adhesive to attach the glass digitizer so you will need to pick up some double sided tape from a stationary shop, not the white padded type but clear thin double sided cellotape. Cut it to size and apply it to the flat top, bottom and sides parts of the inside of the bezel and then press the glass digitizer into place on the tape lined plastic bezel to secure the two parts together. The glass digitizer has a plastic protective film on the front and on the inside section that sits above the LCD, do not remove the inside piece until you are ready to finally re-assemble the Touch completely.
WARNING The round home button itself just sits between the plastic bezel and glass then fits into the hole in the front
be sure it is in place before you join the 2 parts together.
Now you just need to connect the ribbon cable of your new front screen to the mainboard and snap the complete front assembly back into the chrome back.
NOTE: Remember to remove the inside piece of protective plastic from the glass digitizer before you snap it back together. Also try to avoid touching the LCD panel inside the Touch as it is a pain in the backside to clean any finger or contact smudges off it, if you do however be sure to use a lint free cloth to clean it prior to assembly rather than a tissue or other material that may introduce dust, fluff or lint into the unit, there would be nothing worse than finding you have particles stuck under the screen after you put it back together.
If you have broken the LCD panel as well as the glass digitizer and need to replace it then after removing the old glass and bezel as above you need to gently lift the broken LCD screen and flip it over to remove the screws (7-8 from memory) from the base plate that the front assembly snaps into. You will need a quite fine tipped Phillips screwdriver for this. Once you have removed the screws you should be able to lift the bottom plate gently from the top end.
NOTE: the battery is stuck to the bottom of this plate and will lift also so just lift it enough so that you can see the ribbon cables for the battery and LCD underneath. Follow the LCD ribbon cable to the connector and pop it up from the mainboard. There is a broad piece of copper tape that is stuck to the front edge of the LCD that curves around to the bottom of the base plate, just gently peel it from the front of the LCD but leave it attached to the base plate, you should now be able to remove the broken LCD and slide it's ribbon cable out from under the battery.
Run the ribbon cable of the new LCD back up over the battery and press the connector onto to the mainboard, move the base plate and battery back into place, replace the screws to secure the base plate then seat the LCD after removing the protective plastic from the back and press the copper tape that you peeled of back over the edge. Do not remove the protective cover from the front of the LCD until you are ready to snap the front assembly back into place as above.
To make the whole process easier you should work in a well lit, clean, dust free and uncluttered workspace with all the parts and tools assembled before commencing. Have a small container handy to place the screws you remove into so that you don't lose any and work slowly and methodically through the process without getting overly stressed. Although it may seem daunting once you have removed the old front section the rest is relatively straight forward and putting it back together is a lot less stressful than taking it apart.
There is an illustrated disassembly guide for the 2nd Gen Touch
HERE that I found helpful.
Be aware that I am not a professional and offer the above only as a guide that may assist you and will not be responsible for any damage or injury that may occur to you or your device should you decide to undertake to repair your device as I did. Electronic components are sensitive to static electricity, moisture and contaminates and repairs of this nature should only be conducted by a qualified technician.