You can perform all of this in a single button.  The amount of code, however, may be a different story.
First, if you are trying to generate a custom PDF on Salesforce from a Visualforce Page, then you will need to develop the needed Visualforce Page, and its related controller, if necessary. 
Then you will need to create a class that exposes a webservice method and does a couple of things:
1. It will need to call the page - using the PageReference.getContentAsPDF() method. This will return a Blob
2. You can then create the Attachment Record (using the Blob returned from the previous step) and relate it to the Parent Record. Save this.
3. You can also then use the Blob record to create the EmailAttachment and then create the email and send it off.
Once this is complete, you will need to create your button, which is essentially a javascript button that will use the sforce javascript library to call the method that is exposed as a web service.
Below is an example of the class that will generate the PDF, Save the attachement, and email it:

global class PDFGenerationClass {
    static webservice Id GenerateCustomPDFAndEmail(Id recordId){
        //first we need to get the page
        PageReference defaultPage = new PageReference('/apex/PDFPage'); //page location
        defaultPage.getParameters().put('id',quoteId); //passing in id for specific record
        Blob pageData; //variable to hold binary PDF data.
        if(!Test.isRunningTest()){ // for code coverage 
            pageData = defaultPage.getContentAsPDF();
        } else {
            pageData = Blob.valueOf('This is a test.');
        }
        //create attachment
        Attachment att = new Attachment(
            					ParentId=recordId,
            					Body=pageData,
            					Name='Quote ' + DateTime.now().formatLong() + '.pdf'
        					);
       	insert att;
        //create and send email 
       	Messaging.EmailFileAttachment att = new Messaging.EmailFileAttachment();
       	att.setBody(pageData);
       	att.setContentType('application/pdf');
       	att.setFileName('attachment.pdf');
       	Messaging.SingleEmailMessage mess = new Messaging.SingleEmailMessage();
       	mess.setSubject('Email');
       	mess.setToAddresses(new String[]{'somebody@blah.com'});
       	mess.setPlanTextBody('Here is your attachment.');
       	mess.setFileAttachments(new Messaging.EmailFileAttachment[]{att});
       	Messaging.sendEmail(new Messaging.Email[]{mess},false);
        //return the Id of the attachment that was created and emailed
        return att.Id;
    }

Below is an example of what Javascript would go into the button:

{!REQUIRESCRIPT("/soap/ajax/38.0/connection.js")} //include required Javascript
{!REQUIRESCRIPT("/soap/ajax/29.0/apex.js")} //included needed Javascript
//call the acutal service method
var result = sforce.apex.execute("PDFGenerationClass","GenerateCustomPDFAndEmail",{recordId:"{!record.Id}"}); 
if(result != null){ 
window.alert('PDF Generated.'); 
window.location.reload(); 
}

There you have it.