I imported a stick not too long ago and it came through USPS to the UK. What tends to happen is it comes over Customs holds it for roughly a week (might be less for you) and then they charge VAT on it. Parcelforce will take it and charge you 8 delivery so you have to pay both of those payments to Parcelforce and they will deliver it. Failure to pay the charges results in them sending it back to the country of origin.
If you get a tracking number with USPS you can use this to track your parcel even after it is given to Parcelforce (just take the USPS tracking number and put it in on the Parcelforce site and then you will see Parcelforce’s tracking number). Also with this tracking number you can check the status, which is what I did the first time I imported and on the status you will see something like “awaiting payment of charges” or something like that and you can pay the charges before the letter gets to you so that the parcel gets to you faster. If you don’t get a tracking number wait for a letter which will tell you how much you owe them. You can pay for this charge either online or over the phone. I’ve paid both ways before and personally I’d recommend online payment, but thats my preference. If you want a rough idea how much it will cost I can garentee it will be 24 or less. Mine costed 24 because it was an AIAB.
Another good thing about paying online was that you could pick the day you wanted the parcel to come. I’m not sure if they give you that option on the phone because last time I did over the phone was 2 years ago.