Should I convert my MTS (AVCHD) file to another file type before editing with elements 10

Question

I know premiere elements 10 has project settings for working with AVCHD footage but after doing a bit of reading about how AVCHD (MTS) files are a lot harder for your computer to work with I'm thinking it might be better to convert my raw video files to another video file type before editing with premiere elements 10.
I have a reasonably good computer, but it's only a laptop with 361gb free memory, radeon graphics card, core i5 processor and 8GB ram.
If I should convert these files first what file type should I convert them to without loosing too much video quality and where can I find a program to convert them.
Many thanks
Sally

Answer 1

I have a reasonably good computer, but it's only a laptop with 361gb free memory, radeon graphics card, core i5 processor and 8GB ram.
My granddaughters and I have been using one of those to edit videos taken in (two) Sony and (one) Panasonic cameras.  The computer is a mid grade Toshiba laptop that is about three years old.  The cameras were purchased after the computer.  Our computer does not have a graphics card, but the other specs are about the same. 
I know premiere elements 10 has project settings for working with AVCHD footage but after doing a bit of reading about how AVCHD (MTS) files are a lot harder for your computer to work with I'm thinking it might be better to convert my raw video files to another video file type before editing with premiere elements 10.
I didn't read that until after we had made videos.  The issue is the project preset that is set when you open a new project. If you guess wrong, PrE10 tells you so when you slide the first clip to the timeline. 
There is confusion about AVCHD because there is a 1.0 and a 2.0.  The "high" setting for many cameras the last couple of years was 1080p60.  That did not become part of AVCHD until last July.  Now it is and is called 2.0.  PrE10 specs include AVCHD 1.0, so the 1080p60 is "officially" unsupported.   I didn't know that, so I tried a few presets when my files were 1080p60.  A preset of 720p60 worked best. 
The "work harder" part primarily has to do with the preview window during editing.  If it is not going smoothly there will probably be a red line above the clip.  Pressing "Enter", getting a cup of coffee and patience will make the red line go away and the preview will be smoother.  The relationship between project presets and final output is a mystery.  My experience is that the presets have only to do with real time preview and little to do with output.  Output requires an entire re-encoding for the chosen viewing platform.  PrE10 seems to ignore the project presets, uses all the markers set in editing and builds the final products from scratch. 
If I should convert these files first what file type should I convert them to without loosing too much video quality and where can I find a program to convert them.
Steve and Bill invest a lot of time here helping people like you and me.  But, my experience is that they are wrong.  I see no need to convert the files.  Conversion always has the risk of loosing a little picture quality.  PrE10 seems to handle AVCHD fine.  Let it do the final render using the actual source clips.
Sally, consider upgrading to version 11 where AVCHD 2.0 and 1080p60 is included.  I have.  Processing is a little smother.
Bill
PS:  Please, with all due respect to Bill and Steve who work hard here, I disagree based only on experience with 3 cameras and one computer.  User experience varies!