Planning A Backyard Wedding Reception For 250 People

My fiance and I are planning to get married this coming august.we are going to have the reception in his parents backyard,because it is big enough but we need some tips on how to do this.it is for 250 people.and we decided we are going to do a bbq type thing and having famous daves cater.we don`t have a whole lot of money to spend...so if anyone has any ideas on where we can find affordable rental rates for tables and chairs,decorating,invitations...etc.please let me know!also,if you know of any other outdoor places we could hold the reception,that would be great too!because the only downfall to havin the reception at his parents is that the parkng space is limited.any ideas on anything for a casual but yet memorable outdoor reception would be great though!we want to spend roughly 5,000 on everything