Icloud Safe Storage Solution

i agree
so , what is the advice
keep my files on my desktop ?

yes , good suggestions
but what about if i want to reach the files throug my smart phone ?

Put the important files in the Cloud for easy access.

If you need access to all of the files then you can remote access into your computer from phone.  Apps exist for that purpose.

Any example of pre internet encrypt ?

Examples http://lifehacker.com/five-best-file-encryption-tools-5677725

Note that if you are going to use your phone you'd need an unencrypter on that so you can read your files.

And here is the trick

ok , now the question is :
think i used encryption tools refereed in your link , what is the guaranty that no one could decrypt them

NO guarantee.

Extremely unlikely that the average person would be unable to decrypt them.  However a government agency may have the tools to do so.

ok , i got your recommendation about backing up my official data on external drive
, still one thing , any recommendation about your preferable provider to save the normal files on cloud ?

up

Whoops.  Apologies for not replying earlier.

For small amounts of data you can look at DropBox, iCloud, Google and OneDrive.  I also presume that data going to those four is not sensitive data as those four quite probably will supply to various governmental organizations data when asked to.  For iCloud you'd need an Apple product to get an account there.  You can get free accounts for the other products.  For small amounts of data they don't charge, for larger data amounts all four can supply but charge money.  You also need to look at what data formats you intend to be using as well and what devices to access it.  For example if you are using Microsoft products then OneDrive should be considered.  

I use DropBox to store photos and the account is shared by family in various countries.  Nice easy way to share photos.  You can use it for documents if you wish.

I've got Apple devices but I've never had the urge to use iCloud.

Similarly I've got a Gmail account but never had the urge to use Google Docs but Google Docs is a pretty easy way to edit simple documents from anywhere on a good range of devices.

Can't say anything about OneDrive as I've not had the urge to trust anything to Microsoft.